Wahay, nice one Trip, i hope you have fun in college world. What helps depends what subject you are taking, but I guess in the US you have the whole freshman undecided year (my first year was 9-5 work every day).
For me OmniOutliner was invaluable, i used it a lot for notes as it was entirely keyboard navigable and allowed embedding of all sorts of files etc.
OmniOutliner is also very useful as a to do list, and if you are aimign to be a diligent student not a slacker, todo lists do help a lot (though i didn't manage thsi till i was a postgrad).
I found Illustrator invaluable as i used it for all diagrams etc, but i was already familiar with it. If you know how to use its its awesomely quick to illustrate your papers with.
As an undergrad i sadly spent most of my time in word/excel, and hated them. In the end i started doing all my actual text writing in TextEdit then just using word to do formatting and layout at the end.
Parallels and a copy of Windows is probably also a damn good plan for compatibility.
Adium (or another chat client), for time wasting
That and soem nice simple games.
Just whatever you do, do not even think of buying world or warcraft, i now know 5 WoW induced college dropouts.