question about renting and used books

<p>Hello,
I'm going to be a freshman at UMD next year and I'm trying to figure out what makes the most sense for textbooks. I like the idea of buying used so I'm looking into that but I don't totally understand renting - I thought it wouldn't be an option because I learn best by marking up what I'm reading so I assumed I wouldn't be able to give it back, but from the way this guy at the book center talked about it, it seemed like you could mark up a book and give it back and it would be fine. So I have two questions about this:
1) Is it true at UMD that you can rent books and still mark them up?
2) If that's true, does that mean if you buy a used book it might be marked up a lot? Because I don't mind a book being a bit worn but I usually don't like having other people's notes already in the book...
Thanks so much to anyone who can help explain this to me :)</p>