The Legend of Zelda: Majora's Mask/Clock Town
Clock Town is basically the hub of the game. Each three-day cycle begins in Clock Town, and here you will be spending a lot of time doing sidquests and getting to know the townsfolk and their problems. Though you are not obligated to stay here any longer than you have to, the meat of this game comes from the sidequests and subplots that all begin here in Clock Town.
Here are some of the things you can do before heading to the Southern Swamp:
 North Clock Town
North Clock Town is kind of like a park: it has a small playground in the northwest and lots of grass. There isn't too much to do here, though you can get some nifty items here for doing some sidequests.
The first thing you should do is go back into town and find the Stray Fairy again. When you find the Stray Fairy, return back to the Great Fairy Fountain to get the Great Fairy of Clock Town back to normal. Your prize for helping her again is probably one of the most important masks in the game: the Great Fairy's Mask, which will help you find Stray Fairies in temples. When worn, its hair will sparkle when a Stray Fairy is in the room, and if a Stray Fairy has been freed from her prison, they will be attracted to your mask. A very helpful, yet very hideous-looking mask indeed.
 Get the Bomber's Notebook
Jim (a.k.a. the red bandana-wearing Bombers Gang Leader) is still here, and just like before he is trying to shoot down the balloon. If you use your Deku powers to pop the balloon and then switch back to human form, you can once again play the hide and go seek game with the Bombers. If you are in human form, successful completion of the minigame rewards you with the Bombers' Notebook, an item that lets you keep track of the good deeds you've performed. You can help out twenty people in all, and just to get you started on your life of good samaritanism, getting the notebook automatically fills in the first entry of your notebook: The Bombers Gang. Only nineteen more to go!
If you want to avoid playing the game all over again, simply go to the Bombers' Hideout and enter the code you got from the prologue. Enter the hideout, then exit. Jim will rush up to you and, if you are in human form, will give you the Bombers' Notebook.
 Help the Bomb Shop Lady
Stick around North Clock Town until midnight of the first day to witness an event where an obnoxious thief known as Sakon robs the poor old lady at the Bomb Shop. Chase after Sakon and slash at the bag he stole with your sword to free it from his grip. As it turns out, this old lady runs the Bomb Shop with her son, and she repays your kindness by giving you the Blast Mask! This mask allows you to blow up your face with . Link takes damage for each explosion, yet you can actually negate the damage done by the Blast Mask by raising your shield, which means that you now have unlimited bombs. The Big Bomb Bag will also become available in the shop if you purchased the Bomb Bag prior to this. If you fail the event, then the Big Bomb Bag will be put on sale in the Curiosity Shop.
 Deku Scrub Playground
Use the Deku Flower near entrance to the Great Fairy Fountain and fly over the fence and enter the Deku Scrub Playground. The Deku Scrub Playground is open every day from 6 A.M. to 11:30 P.M. Each game costs 10 rupees to play and winning earns you 50 rupees. Completing the game three times in a row scores you a Piece of Heart. To play, you need to use your Deku form to fly from platform to platform and collect all the rupees without falling to the floor. On Day 1, the platforms move vertically. On Day 2, they move horizontally. On Day 3, some platforms move vertically and others horizontally. You have plenty of time to grab all the rupees, so be sure to take it slow so that you don't fall off the platforms.
 West Clock Town
West Clock Town is more business-oriented than other areas. There are lots of shops and other things to do here.
 Swordsman's School
The Swordsman's School is open all day long on Days 1 and 2, but it closes at 11 P.M. on Day 3. The School offers two courses: the "novice" course costs 1 rupee and goes over the basics of sword fighting. The "expert" course costs 10 rupees and is more of a game than a learning experience: here you must slash logs to earn points. The amount of points earned depends entirely on which attacks you perform. Using a Jump Attack (target the enemy and attack with while your sword is unsheathed) against all of the logs will give you a perfect score and a Piece of Heart.
 The Post Office
The Post Office is open from early in the morning until midnight, but before 3 P.M. it's empty. Return after 3 P.M. to play a game with the Postman. In this game, you need to stop a clock with so that the time is exactly 10 seconds, right down to the hundredth of a second. A timer appears for the first couple of seconds, but disappears after that. This game can be rather difficult -- if you find it too hard to count to 10 seconds exactly, then use a stopwatch to keep track of the time, or have Link wear the Bunny Ears, which will allow him to see the timer for the rest of the game. Stopping the clock at 10:00 seconds nets you a Piece of Heart.
 Clock Town Bank
The Clock Town bank allows you to store and withdraw rupees, but it also offers a much more important service: it keeps your money safe through time-travel. If you deposit 200 rupees in the bank, you will be rewarded with an Adult's Wallet, which lets you hold 200 rupees. Depositing 5,000 rupees earns you a Piece of Heart.
 The Lottery Shop
Tickets are sold at the Lottery Shop from 6 A.M. to 5:59 P.M. daily, and Tickets can be redeemed from 6 P.M. to 11 P.M. daily. The winning numbers never change between cycles, so by entering the same winning numbers from the previous cycle, you'll win 50 rupees. This strategy of getting free money entails returning twice every day, so it can be a bit of a hassle.
 The Bomb Shop
A Bomb Bag is absolutely necessary, even if you have the Blast Mask, so it would be a good idea to buy one here for 50 rupees. Buying bombs -- or ammunition of any kind -- is generally a gyp, so don't bother buying bombs. Bombchus can be fun but are not really useful, and the Powder keg won't be important until later in the game.
If you saved the old woman on the first day, the Big Bomb Bag will be sold here for 90 rupees.
 The Trading Post
The Trading Post sells some ammunition, potions, and a shield. The Trading Post is generally very useless: Potions are not really useful, and ammunition can be found anywhere. Fairies can also be found in the wild. The Hero's Shield can be purchased if a Like-Like ate yours, but you can always just kill the Like-Like to get it back.
 The Curiosity Shop
The Curiosity Shop is a pawn shop that sells stolen items. It is open from 10 P.M. to 6 A.M. The Big Bomb Bag can be found here if you failed the Bomb Shop Lady Event. Your sword and your empty bottles can be purchased here if they were stolen by the Takkuri in Termina Field. The shop does sell an exclusive item here, however: the All-Night Mask. It costs a whopping 500 rupees, and it is necessary in order to obtain a Piece of Heart from Anju's Grandmother.
You can also sell items in your empty bottles, such as Poes and Gold Dust, to the Curiosity Shop Man.
 East Clock Town
East Clock Town serves as the town's entertainment district. There is plenty of fun to be had:
 The Milk Bar
The Milk Bar opens at 10 A.M., though it's only just for cleaning. At 10 P.M. the bar opens up to Milk Bar members only. In order to access the Milk Bar after 10 P.M. and complete the sidequests here, you'll need a special mask that you cannot get until later.
 The Mayor's Office
From 10 A.M. to 6 P.M. The Mayor's Office is open to the public. The mayor is a bit preoccupied with the current moon situation at the moment, but his wife, Madame Aroma, is more than willing to chat. She will solicit your help in locating her lost son, Kafei, and will give you Kafei's Mask in order to help with the search.
 The Stock Pot Inn
The Stock Pot Inn is home to many characters who will fill your Bombers' Notebook, and it is also home to Anju, a character who plays a major part to a massive sidequest that can be started now but cannot be completed until later. If you speak with Anju at the front desk in any form (except Deku Link) at 1:30 P.M. then you can tell her that you have a reservation at the inn. Strangely enough, there is someone who reserved a room under your name (turns out, it's a Goron who happens to share your name) and Anju will give you the Room Key, giving you access to your own room at the inn.
On Day 1 if you speak to Anju with Kafei's Mask on, she will request that you meet her in the kitchen at midnight. This will let you get started on the Anju and Kafei sidequest, but you won't be able to complete it.
If you want to pass time, you can speak with Anju's Grandmother and have her read you a story, which speeds up time by a certain amount depending on the story.
 The Treasure Chest Shop
From 6 A.M. to 10 P.M. you can play a fairly simple game that involves running through a randomnly-generated maze to get the treasure chest at the end. The prizes you get depends on what form you play through the game as: as a human you'll win 50 rupees, and as a Deku Scrub you'll win Deku Nuts. Be sure to come back once you have your Goron and Zora forms.
 South Clock Town and the Laundry Pool
There isn't much to see or do in South Clock Town and the Laundry Pool. You can find free rupees in the Laundry Pool's river and in the boxes beside the bench, and you can use the Deku Flower in South Clock town to obtain two treasure chests: 50 rupees on the scaffold on the third day and 20 rupees on the straw roof just past the scaffold.
On the night of Days 1 and 2 speak with the Organ Grinder, Mr. Guru-Guru, who is sitting in the Laundry Pool, and listen to his troubles. Just from listening to his story you will get the Bremen Mask, which allows you to control animals by holding down . This event will complete the Mr. Guru-Guru entry in the Bombers' Notebook.
Before you continue, you should go around the Clock Tower to find an Owl Statue. Hit it with the sword to activate it. This is where you can temporarily save your game, and it will also become useful in another way early on.