Assuming your college has everything set up for DHCP, you should pick up their IP address, which allows you to access their network. No internet?
Try pinging a website. (Start - Run - Cmd - type: ping www.yahoo.com)
you should get something like:
Pinging www.yahoo.akadns.net [22.214.171.124] with 32 bytes of data:
If you get this, you can get out to the internet, if not, you may be limited by your college to access the internet from your dorm?
try going to webpages like www.yahoo.com, www.microsoft.com, www.google.com to see if you're able to pick those up.
if you get any errors, write them down and post them here, it'll help us figure it out faster.