I usually buy my textbooks on Amazon or UNLV bookstore (a.k.a. overpriced bookstore for last minute textbook purchase). Located across from Student Union.
1. You can sell your textbooks here but I recommend you not to, and to instead sell it on Craiglist or even ask around. I had English 101E/F textbook that I purchased brand new for over $60. I had no highlights/markings/rips/tears or anything. Barely used/looked brand new and I got $16 out of it which is not even half of what I paid.
Money can be used as in-store credit which can be used right away, or stright to you but will take around two weeks.
2. If you are buying or renting books, this is a good place. I bought books for two classes and my total was around $40 which would have been over $200 if purchased at UNLV bookstore. Price is cheaper, if not same as Amazon.
3. No AC in the store and line moves slower than a turtle.
4. 48 hours return policy. That is for a FULL REFUND. You also need a reason for a return. If you drop a class then you have to bring a proof to show that you withdrew from a class. If you no longer need a textbook then you need to bring a note from your professor saying that textbook is no longer needed. I find their return policy somewhat ridiculous but that's the rule.
5. For rented textbooks, you are allowed to put marking or highlight, but that is only for 20-30% of the entire book. You can highlight and write little notes as long as it doesn't obstruct the text. Must be minimal.
I would come back for all of my textbook needs. It's nice to have a textbook in good condition that is in the same price range as Amazon. Recommend this place strictly for buying/renting, definitely not for selling.