Save money on textbooks
I wish I knew about AbeBooks and buying online when I was in university. I did what I could to stretch my budget but a good source for used books would have been so valuable, I did learn a few tricks that might be helpful for students today.
Ask the professor if an old edition is acceptable. The best textbook deal I ever found was a $5 statistics book that I was able to use for two classes, and because a friend of mine had taken the class the semester before I knew that an old edition was acceptable for the class early enough to buy the cheap copy; $2.50 per course in textbooks was worth the bit of snooping in that instance.
Checking with classmates is also a good way to find out which books are really required and which books you can share with a friend.
Another often overlooked area for cheap books is English classes. The books are a lot cheaper then science texts but the poetry collections and classics like Chaucer and Shakespeare and be picked up dirt cheap on the internet. They may only be $5-$10 in the bookstore but they’re only $1 on AbeBooks.