Well I've started up at Purdue (Comp Engineering), things are pretty normal until Friday and Saturday night. This is when campus turns into one huge party. Most freshman have no clue how to get into parties. I'm going to try to help all of you out here (as I learn myself).
The first thing to do is find a large cluster of Frat houses. Once you've located this you are half way done (it really is easy). Most frats have someone telling random people to go away until about 2:00am. We don't have time to wait that long...we do want to get into the party while it's the best (11:00-1:00 are the prime hours). Act cool while approaching the frat...try to seem liek you belong there. If you see someone you think is a brother at the house, ask them where "Steve" is. For some odd reason every frat has one guy named Steve. The guy will most likely have no clue where "Steve" is. So then ask him if he minds if you look around for him. Generally the guy will have no problem and let you walk right in.
If those first steps don't work...try another house *shrug*..."Steve" has to be somewhere. Once you get into the party try to figure out a couple guys that are brothers in the house and find out their names (this way we don't have to look for "Steve" any more ;) ). Most frats will have some sort of bar. Go up and ask for a beer.
There really isn't any big secret to it all. The hardest thing about the whoel ordeal is getting through the door for the first time. After you go a few times, the guys will start to recognize you and then assume you do know someone. Don't cause problems or be too wild and you will always have some place to get free beer.