orion9, before anyone can give you suggestions on what you should learn, we need to know your goals. if you just want to "hack" (i personally like the older definitions better) websites and beat the challenge then it can be relatively simple. because you are in college and learning C im assuming u are a little more serious about it than that and actually want to make a career out of it.

find out what you love about computers and what you want to do. then find out how to go about getting there.

i can definately sympathize with wanting to learn as much as i can about computers as humanly possible. im a sophomore in high school and am teaching myself 2 languages (perl, C++) and learning a 3rd at school (python). im setting up a linux cluster (with possibly a DOS/Unix dual boot mixed in) in my basement out of recycled computers from friends. Im already planning my senior project (an IDS cluster in the schools network) while most comp. sci. students dont really care. as you can tell im a bit of an over achiever so i have to say thanks to all those guys who just posted about slowing down and making sure you can do what you love to well and then moving on to other things to enhance that.

hope you are succesful in your studies
-Godsrock37