I definitely recommend going the online route, JUST to find out what books you need. A link to UCF's on-campus book store: http://ucf.bncollege.com/
There, you can put in your semester and class code to find out exactly what book you will need for the class. Waiting until the first day of class is a financially good idea, as some professors will not even require you to buy the book.
It's also a good idea to check other resources, such as half.com, to find the best price on a book. I was able to pick up a book and solution manual for $60 total, whereas the UCF book store wants around $160 for used copies!