[Fryza]

1) Honestly, most don't. Some even speed it up by being made of poor materials, or sucking power from the console. Talk to people at a local GameStop or Best Buy about it, and they can give you better info than me shoddy text. As long as the console is on a smooth surface, sideways, and is ventalated (and shitty spelling to boot), it'll be fine for the most part.

2) Depends. The best retail multiplayer games are COD4, Gears, Halo 3, and Madden 08. Bioshock, Mass Effect, and Assassin's Creed are the best single player games at the time. Any of those games will keep you entertained probably, since they're all good stuff.

3) You need to either use a wireless game adapter or run an ethernet cable from your computer/router/modem into the console. I think a phone/television jack might work depending on your connection. You may have to open ports to connect, or just to make the connection open.

If you need help, I recommend this as it will give you pretty good instructions, and links to decent pages if that one doesn't suit you. Microsoft has some stuff on the main site as well...