About buying textbooks.
Amazon marketplace is a good place to look, but the best time to buy is the end of term, when everyone puts their books up for sale, because they've finished with them, but no one buys any until the next term starts, so find out what books you'll want in advance. Also, most departments run their own book sales don't they? I know geography used to. Also, also, the book fairs in the union often have text books, and sometimes they have one you'd like and they're nearly always less than a fiver.
What some nasty people do is get them out of the library, (£10? fine maximum) then wait until the end of term when they'll threaten to charge you for the book and return it. Don't do that, it pisses everyone off.