Assassin's Creed II/Sequence 1: Ignorance is Bliss

The first sequence is to familiarize you with the basics of the game. These include fighting and free running, and how to perform beat up events and courier assignments. In addition to learning new actions, certain gameplay mechanics that are used throughout the game will be explained, such as viewpoints, objective markers, feathers and restricted areas. From a story perspective, this is where Ezio gets his reason for becoming an Assassin as well as some of the tools of the trade.

Boys will be boys
You start out talking with your friends until Vieri de' Pazzi shows up and throws a rock at you. Accept the mission and you'll begin brawling with the enemy gang. You can now punch, block, counter and grab. When grabbing, you can then headbutt (head button), punch (armed hand button), knee (legs button) or throw (unarmed hand button). The first wave consists of four guys, after which your brother Federico will show up to join the fight. The easiest way to beat your enemies is to simply block and counter. When you've taken out enough of the second wave, Pazzi will call his boys back for a retreat.
 * Memory start: Automatic
 * Reward: 100ƒ

You need some money for the doctor, so search the downed bodies by holding the unarmed button while standing over someone. You can search incapacitated enemies whether they're alive or dead, although it's not worth it during the game as they only ever have a couple florins on them. This action is also how you loot chests, and it takes about two seconds to finish. Search the bodies around you until you've found 200 florins (they make it easy on you by putting a lot more money on these guys than you'll normally encounter in the game).

You should see the other guy
You need to follow Federico to the doctor, which takes you over a building to show you how free running works in the game. You'll see his status indicator is blue above his head, but it's not necessary to lock onto him for the mission. Hold down the high profile button while moving to jog, and hold down the legs button as well to sprint and free-run. Follow your brother, but stay behind him and just go where he goes. If he's climbing and jumping, make sure you're holding the legs button so you'll perform the same action. Run down the street then jump across the posts to a landing on the side of the building. Climb up the building and cross the roof to the other side where you can jump down to the doctor.
 * Memory start: Talk to your brother next to the bodies you just looted.
 * Reward: -200ƒ

Sibling rivalry
All you have to do is climb the church across from you and enter the white, swirling lights on the roof. Throughout the game places where you need to be will be marked in this manner. Federico heads off to another building to jump across the roofs, but you can run right up to the front of the church and start climbing at the door behind some people talking. It shouldn't be a problem to make it up there before your brother. When you get to the top you'll follow your brother up the nearby tower.
 * Memory start: Automatic
 * Reward: None

Nightcap
You won't be able to see your next objective marked on the map until you synchronize the viewpoint in the area, so walk out onto the wooden plank sticking over the side of the roof and press the head button. When you look at the map now, you'll see the area surrounding the viewpoint has been revealed, showing your objective and a couple shops. In addition, you will also see all the other viewpoints in the district. Perform a leap of faith from the tower by moving off the platform while holding the high profile and legs buttons. When Vieri and his thugs have passed, exit the haystack and head northwest to your girlfriend's house.
 * Memory start: Automatic
 * Reward: 100ƒ, Races unlocked

Pazzi's men will be marked on your minimap with red dots, and if you go near them they will become suspicious and eventually attack you, so steer clear of them. When you get to white marker under her window, she'll come out to see who it is. Climb up to her window when she's done talking. Once inside you'll have a cut scene with quicktime events. If you press the buttons when indicated, Ezio will perform an alternate action.
 * 1) Press the head button to kiss Cristina, otherwise you hug.
 * 2) Press the unarmed hand button to take off her dress, otherwise you throw her on the bed clothed.
 * 3) Press the head button to make love to her, otherwise the scene cuts away.

The next morning, Cristina's father finds you in bed with her and chases you out calling for the guards. You'll need to lose the guards and get back to incognito status. At this point, they're not very good at chasing you and they don't look very hard when you're hiding. Watch your minimap as you run away and try to get outside the yellow circle you see, which indicates the area where they're actively looking for you. The blue dots on the map, which only appear when you're being chased, show you where good hiding spots are, such as hay carts or benches. When you've either spent enough time in hiding or enough time outside their search radius, you will become incognito again and the minimap will lose the yellow or red ring around it.

Paperboy
This is a simple delivery mission where you take your dad's letter to Lorenzo de' Medici. Whenever you get a letter in the game, you can read it in the Database. Your destination is in a little courtyard to the southeast of your house. The alleyways leading into the courtyard are guarded by Pazzi's men, so if you don't want to fight them, you can get in from the roofs above. Either climb down a ladder on the side or jump off the edge into the hay cart. You'll see a man highlighted in white at the west end of the courtyard. Talk to him to deliver the letter, then return home to let your father know Lorenzo is out of town. The door to your house will be highlighted this time, and you can press the unarmed hand button to interact with it.
 * Memory start: Talk to your father in front of the Auditore house.
 * Rewards: Courier assignments unlocked

Beat a cheat
You'll need to find your sister's boyfriend Duccio and beat him up for her. He's in the northeast part of the district, talking with another woman on the south side of the Santa Maria del Fiore. When the you walk up to him in the cut scene, there's an opportunity to get a quick punch in with the armed hand button. When you have control, beat him senseless.
 * Memory start: Talk to your sister in the garden in front of your house.
 * Reward: 100ƒ, Beat up events unlocked

Petruccio's secret
You'll have three minutes to collect three feathers for your brother. Start out by climbing the barrels with the white sheet over them right next to him up to a landing, then over to the roof with the feather he was pointing to in the cut scene. Follow that roof around to some wires crossing the courtyard to another roof, then climb up and head west across the roofs to the next one. Keep following the roof around to the south and pick up the last one before heading home. Once you have the third feather you're no longer timed, so go back to your brother any way you like. The three feathers you collect don't count towards your feather collection.
 * Memory start: Talk to your brother in front of your house.
 * Reward: 100ƒ, feather locations unlocked

Friend of the family
In this simple mission you follow your mother to Leonardo da Vinci's house and then carry back some of his things. If you get too far away from her, you'll get a warning message to close the distance. After meeting Leonardo, you'll walk back to your house. Pick up the box with the unarmed hand button and lead the other two back to your house. They'll follow you even if you run, so there's no reason not to. If you alert Pazzi's men along the way, you can still drop the box in front of your house, but you'll need to deal with them and become incognito before ending the memory.
 * Memory start: Talk to your mother in the garden in front of your house.
 * Reward: 100ƒ

Special delivery
Your father sealed the letters, so you can't read them – you'll just have to deliver them. The two letter deliveries are to the south and southeast of your home, while the pigeon coop is on a rooftop almost directly east. You can do the errands in any order, and the letter deliveries are marked with the swirling lights. The delivery to the south is inside a courtyard with a street entrance on the west side. The other delivery is up a ladder to a rooftop with a guy standing beside it. When you retrieve the message from the pigeon coop, you'll be prompted to use the contextual camera button, which will let you see a group of men running down in the street, heading toward your house.
 * Memory start: Knock on your front door.
 * Reward: 100ƒ

Jailbird
Your father and brothers have been taken by city guards to the Palazzo della Signoria, which is directly east of your house. If you look at the map, you'll see the location is marked by a red square, meaning it is a restricted area. When you venture into a restricted area, you become automatically notorious, meaning guards will attack on sight. Start climbing the building from the east side, which can be accessed from nearby rooftops.
 * Memory start: Knock on your front door.
 * Reward: 100ƒ

There's an archer on the first level and he patrols back and forth across the whole area. When he's not looking, climb the ladder in the center of the area up to the next level. Here there will be two guards; one stationary on the south side and a roving one on the other side. When the rover has his back to you, run across the area and start climbing the tower in the middle. When you get up as far as you can go, shimmy around the building to the left and climb up the single window on that side. This will take you to your objective marker and you'll talk with your father. When the cut scene is over, you'll drop down to the haystack below. You're no longer in a restricted area, but the archers still don't want you up there. You can get down quickly by jumping off the wall behind the haystack to the hay cart below.

Family heirloom
Inside your house, hold the head button to use eagle vision. Once you've seen the hidden entrance in the fireplace, you'll be able to enter it by interacting with the unarmed hand button. Go inside and open the chest to retrieve your father's items. You have a sword now, and if you select it – either from the quick button or the selector wheel – you will attack with it instead of your fists when pressing the armed hand button. You can block and counter with the sword, just like you do with your fists.
 * Memory start: Knock on your front door.
 * Reward: 100ƒ, Assassin Robes, Broken Hidden Blade, Codex page, Plain Cape, Common Sword

Head outside to deliver the letter to Uberto Alberti, and you'll be attacked by two guards who also have swords. The fight is easy enough by just attacking them repeatedly, but to take no damage, just block and counter. The delivery can be made at a house to the southwest of your home.

Last man standing
Just up the stairs to the east of you is the acquittal of your family, so head over there to start a cut scene. When the cut scene is over, you'll need to escape from the guards and regain your incognito status. Run away like always and when you get outside their search radius, find some cover. They're not very good at climbing, so the easiest way to lose them is to climb over a building.
 * Memory start: Next to the town crier in a courtyard east of your home.
 * Reward: None