Actually there are a couple of things you might want to do in addition to the basics. BTW, all of this will require entering the web-based router setup so you should probably read the manual. You can get to your router's web-based setup page by opening your web browser and typing in the address bar either: 192.168.0.1 or 192.168.1.1
The address will depend on the router, some use one some use the other. After you get there it will ask for a username and password, this is where the manual comes in handy.
1.) Change your router's default LAN IP address. It should be either 192.168.0.1 or 192.168.1.1
Change it to something like 192.168.150.1
Make sure to check it's default gateway (in the status pages) and make sure they're not the same
In theory, if you're on a network with multiple routers, it shouldn't matter what IP they assign themselves. They should keep their inside LAN IP and outside WAN IP seperate, and maybe in comercial routers it works, but I've seen it a hundred times, if your store-bought $50 router has the same internal IP as the router it's connected to then it may cause random connection issues.
2.) There's no telling how many other wireless routers may be near you. All those shiny-new 2.4Ghz devices are usually taken out of their boxes, plugged in and never touched again until something doesn't work right. This means that the majority of them are using the default settings. This can be a problem if several of them are using the same network ID. So change your router's SSID (under wireless setup). Make sure to use something unique but, for God's sake, don't use your name or anything else that can identify you personally, it's a safety thing.
3.) For the same reason as above, change your router's broadcast channel setting (should also be in wireless setup). By default most routers use channel 6. This can generate a substantial amount of interference. The best channels to use are 1 or 11 but since you're in a dorm and probably don't need to get a range of several hundred feet you can use any of the channels other than 6.
4.) For the love of God, set a WEP key for your wireless network. This will also be under wireless setup, probably on a security tab. This will require anyone joining your wireless network to provide a passkey. Without it anyone with a wireless card can jump on your connection and surf away, and any kiddie porn they check out is registered to your IP address when the FBI comes to track them down.
That's about it for now, I may think of some other stuff later. If I do, I'll post it as well.
