Assassin's Creed II/Sequence 7: The Merchant of Venice

After the "Building blocks" memory, the next three open up at the same time and can be completed in any order. After "Monkey see, monkey do", "By leaps and bounds" will become available, and after "Breakout", you'll have access to "Clothes make the man".

Benvenuto
A pretty simple memory, just follow Alvise da Vilandino around as he gives you and Leonardo a tour of this district of Venice.
 * Memory start: Talk to Leonardo right where the sequence starts.
 * Reward: 1,500ƒ, Assassination contracts unlocked

That's gonna leave a mark
As you're contemplating how to get into the palazzo, some thieves distract the guards and a woman attempts to scale the wall. She gets an arrow in her leg for her trouble and needs your help to get her to safety. Start out by following Rosa. She likes to fight anyone she sees, which means you'll also have to fight them while making sure she doesn't lose too much health. Eventually you'll run into a group of her thief buddies and you'll have to carry her the rest of the way. Don't bother stopping to fight, just keep going and let the thieves keep any enemies occupied. The only time you have to fight is if a pursuit guard follows you and at the end where you must become anonymous before dropping Rosa off.
 * Memory start: Enter the white marker to the west of the Palazzo della Seta.
 * Reward: 4,000ƒ

You'll hand her off to her friends, who will take her by boat back to their hideout. You need to go along with them and take out archers along the way who might damage them. Head down the left side of the canal they're going down and take out the soldiers along the way. When you run out of ground, free run along the beams on the sides of buildings to continue following the boat. Watch the minimap for red dots signifying a guard you should take out. This requires going back and forth between the two sides of the canal. It's best to stay a little bit ahead of the boat so they don't take any damage. When they make it out to open sea, get up above them and take out the archer on the corner of a far building. The next archers are down by the fast travel station, so drop down to take them out, then keep heading around the backs of the buildings facing the water. Shortly thereafter, you'll see them turn into an outlet and go under a building. Head over that building's roof and drop down to the small inlet on the other side to meet back up with them.

Go pick Rosa up and walk in the direction the camera shows you, then put her down on a table where indicated. Follow the quick time events during the cut scene after which you'll meet Antonio.

Building blocks
Nothing to it, just knock on the door to hae a conversation with Antonio and drink some coffee if you want.
 * Memory start: Knock on the door near where the last memory ended.
 * Reward: 1,500ƒ

Monkey see, monkey do
After watching Franco perform the climb leap, run up to the wall below the scaffolding and go up the same way. Perform three climb leaps to the top of the structure and enter the white marker there.
 * Memory start: Talk to Rosa in front of the thieves guild in the San Polo district.
 * Reward: 2,000ƒ, Climb Leap skill

Cleaning house
You'll need to take out three targets around the city. One is nearby to the northeast, one is down in the south east and one if very far to the east. You'll find the one nearby on a ship out on the water, accessible by a series of poles leading to it from behind the fast travel station. There are guards in two smaller boats on each side and a lot on the main one, so your best bet is to swim up to the main ship from underwater. From the fast travel station, wait until the closest guard and the target on the main ship aren't looking your way, then jump to the first pole and do a jumping dive underwater and swim to the side of the ship. You can turn your jump into a dive by pressing the legs button in mid-air. This should get you to the ship without being seen, after which you can climb the side and position yourself below the open section of railing where the target walks by. Do a ledge assassination when he comes around, then swim underwater back to the docks and head to the next target.
 * Memory start: Knock on the door to the thieves guild.
 * Reward: 2,000ƒ

The southern target is on the rooftops in the center of the green circle, and he will attack when he sees you. Head up there and take him out by stealth, push him off the ledge or just fight him normally. You'll find the final target in a market on the east side of the city. He's walking around with a friend of his and there are some groups of civilians you can blend with. Although there are plenty of ways to take him out, as he walks fairly close to both groups of people and a haycart, it's a good idea to get him when he stops at the edge of the canal so you can double-assassinate him and his friend at the same time.

Breakout
Three separate groups of thieves are being held captive somewhere in the city, each in a restricted area. One is directly south of where the memory begins, one is to the southwest and the last is in the northwest. The way to make each of the prison breaks easy is to perform a leap of faith from the rooftops in a haycart near the cage. Listen to the guards talking to the prisoners and each other, and when a single brute is left alone guarding the cage, quickly hop out of the haycart and back in. This will alert the brute, who will walk over to investigate, leaving him open for a stealth assassination from cover. Once he's been disposed of, free the prisoners and return to the rooftop where Ugo is waiting.
 * Memory start: Talk to the thief Ugo on the roof across from the east side of the Santa Maria Gloriosa Dei Frari.
 * Reward: 2,500ƒ

The southern area can be accessed from the ground, while the rest are blocked off on all sides with guards. For the southern area, you don't have to climb up to the roofs to get out of the restricted area, but be careful not to run into a roving patrol nearby. The brute in the south is the only one you can air assassinate from above without it alerting the other guards.

By leaps and bounds
You'll have five minutes to get to the top of the structure, which is extremely generous. Head around the side of the building to the south and climb to the roof of the next building over. From this roof you can jump back over to the tower and take the white bricks up to where you'll need to start using the climb leap to continue. At the top of the tower, perform a leap of faith from the wooden board and talk to Rosa at the bottom.
 * Memory start: Talk to Rosa in front of the Santa Maria Gloriosa Dei Frari.
 * Reward: 2,500ƒ

Clothes make the man
There are three chest you'll need to loot for archer disguises. The closest is just to the south, the next is farther east and the last is even farther east and northerly, in the southern corner of a restricted area. The first chest is guarded by four soldiers in a tiny alley. They've left the rear unprotected and it can be reached from the canal, so hop along the poles sticking out of the water, and loot the chest behind their backs. Alternatively, you could distract them with the thieves across the street from them.
 * Memory start: Talk to Ugo the thief at docks by the Thieves guild.
 * Reward: 2,500ƒ

The next chest is just to the east of the first one, but as the guards have their backs to a wall, you won't be able to sneak up behind them. Hire the thieves just to the north of the guards and have become a distraction so you can loot the box. They take off in the direction of the next chest, to be careful not to get tangled up with them when you move on. Head down the street to the next chest, which is guarded by a group of four. Here you'll have to also watch out for the roving group of four soldiers and the fact that you're right next to a restricted area. Hire some thieves from around the corner and have them distract the group guarding the chest. You'll then be free to loot it, as it's not actually within the restricted area.

The boat you need, however, is in the restricted area. Just run straight to it, as once you're on the boat you can easily outdistance your followers to regain anonymity. Head west and it's a straight shot back to the white marker at the docks where you started.

Everything must go
After you've talked with Antonio, head to the Palazzo della Seta, far to th east and take out the five archers on the rooftops nearby. The archers are all walking on wooden platforms that would let you perform ledge assassinations, but they're just normal rooftop archers, so you can just go in an stab them all and throw them off the roofs if you don't want to take the time. When they're all dead, you'll be able to meet up with Antonio, Rosa and Ugo in a secluded alleyway, just west of the palazzo. Your next objective is to assassinate Emilio Barbarigo.
 * Memory start: Knock on the door to the Thieves guild.
 * Reward: 5,000ƒ

First you need to find a way onto the palazzo grounds, and the entrances are all guarded. One way is to jump over the fence from the side of one of the buildings just west of the palazzo. If you climb down from the roof, you can jump from a place where it won't hurt when you land. This will put you behind the guards and you can climb up the western face of the building to the roof. Climb up to the balcony on the southwest corner and use a ledge assassination on the guard there, then continue climbing up. When you get to the roof, or at certain heights if you went a different way, a cut scene will trigger where you can see Emilio and his friend talking as they walk downstairs to the open doorway facing the canal on the northern side. After his friend leaves, Emilio will walk back upstairs. From the south side of the roof you can air assassinate the guard on the walkway below you, but you may want to take out some of the archers up there first. Don't worry so much about alerting the guards, because you don't have to escape after taking out Emilio. If you take too long, Emilio will eventually escape on his boat, but you have plenty of time so don't rush.