<p>Definitely the Litvin book (you can find it at <a href="http://www.skylit.com/index.shtml)%5B/url%5D">http://www.skylit.com/index.shtml)</a>. While glucose101 is correct in saying that, in an ideal world, Comp Sci should probably be a "hands-on" subject, a class isn't absolutely necessary. The test questions are quite straightforward, so you don't need to have a lot of programming experience - I had never actually written code in my life (just learned the syntax), and the comp sci AB exam wasn't too bad (got a 5). Since there aren't any involved questions, once you've learned the syntax, you've learned basically all you need for the test.</p>