When should I get books?

<p>When should I get my books for classes? I can probably get good deals online at Amazon or somewhere else, but can't the professor change the edition on the first day of class? Are the editions posted on the LSA course guide up-to-date or are they from last year? Are the prices at the book stores in Ann Arbor much more expensive compared to online stores? I learned from my orientation that it is easy to return books from a book store near campus (as long as you have the receipt).</p>

<p>Thank you in advance!</p>