Megaton is a town in the Capital Wasteland, slightly north-east of Vault 101. Megaton is built primarily out of scrap metal. There is an atomic bomb in the middle of town. There is a saloon, doctor's office, trader, restaurant and other residential structures.
Arm/disarm Megatons atomic bomb, both result in similar rewards. However, a lot of negative karma comes with arming it. Requires an Explosives skill of 25.
Help Moira (Caterside Supply owner) make a wasteland survival guide. This is a long, long sidequest. It yields some easy experience though.
Fix the leaks appearing around town coming from the water purifier. And later give the owner scrap metal to keep it running. He will buy it for more than its market worth. Requires a repair skill of 30 for initial quest.
Potential companions include...
Jericho: A retired raider, requires bad karma.
On a side note: There is a strength bobble head in Lucas Simms' house on his desk. There is no reason not to get it, it works towards achievements and most of all gives a permanent +1 to strength.
SPOILER: Maybe, not really? The atomic bomb quest results in housing. It comes with a bed, a robotic butler, and plenty of places to store loot. It should be done before continuing with the main quest. Your new butler - if you obtain him that is - has a variety of options available through dialogue. These being to tell jokes, give you a haircut and provide you with clean bottled water. Inside you house there is quite a bit of loot, a bed and multiple sources to regenerate your health. Also, through Moira, you can purchase upgrades like a Nuka Cola machine and Chemistry Set which chill Nuka Cola (increasing the value) and creating chemical substances (drugs,stimpaks ect) respectively