I'm only 24 and so I've still got the whole college experience fresh in my mind (probably gonna go to grad school too).
Although my nickname I have now is a new one, I actually came to this site my last year of high school (my my, that was about 6 years ago). I spent the summer before I started college reading everything I could on this site. I had been a "nice guy" who was also shy when I started.
Anyway, I made the effort to change. And one rule I had for myself, was to approach any and every girl that I could without going out of my way to do it.
Meaning, before every class (especially on the first day of class) most people would get to the classroom before the professor did. Well that's prime time to start some convos.
This is exactly how it will be (especially if you go out of state): People will be standing outside of the class (or even sitting inside) waiting. And everyone will be quiet, looking down or at a map of the campus or something.
Start talking. Just pick someone (even if it's a guy, cause you can be a connector - I'll explain in a second). Pick someone and ask them where they're from. If they're local, then you're automatically interesting because you're out of state (and you need someone to show you around!). Ask them what they're planning on majoring in and where they're staying and blah blah. So many easy questions to ask because everyone is there for the same reason.
THEN you start playing connector. If you dwell on just one person (esp a girl), you might over do it (or appear to over do it). As soon as you are ready, turn to the person next to you or across from you and say, "what about you, where you from?" And so on. Get everyone talking and all of a sudden you're the social guy who got everyone to loosen up. Plus, making lots of aquaintences right away is perfect because it'll get you invited to parties (and believe me, the 1st week of freshman year is nothing but parties). Hell, orientation is nothing but parties. Go to that if you are going out of state. I hooked up during orientation. Some girl thought I was cute and she was kind of drunk and she took my pants off in the middle of the room where there was a party and we excused ourselves.
Ok, if you're staying in the dorms go to floor meetings. Most guys will ditch the meetings because it's "gay" to go. But guess what? The girls will not ditch the meetings (at least not most of them). Mingle and flirt with the girls from your building/floor and you're in for the entire school year. This is so easy to do it's not even funny.
Or, if you're staying in an apartment, invite people from your class to come and party at your place. Make it BYOB and if you can invite 10 people, 50 will show up.
If you're at a commuter school and live at home, you better get into a frat or join some clubs.
Anyway, that should get you through the first week of college (for whoevers interested).