Stack Overflow: You may or may not have heard of Stack Overflow, but have you really used it? Have you looked for answers - probably yes, but have you posted questions? You will be doing both extensively during the course, so you might as well get used to it!
Google Google is your friend. You know this of course. Almost any technical problem you encounter has been solved and written up by someone. Google it. Ask Mother Google. Ask The Google!
Best of Rails Help
Rails Guides Highly readable and concise (yet comprehensive :) guides to the most important parts of Rails. Often better than any book or manual.
Rails Casts This web site contains hundreds of free screen casts that give step by step explanations on all sorts of use cases of rails. As the series has been going on for years, and has been in suspended animation since this June, you will see videos that talk about old versions of Rails and obsolete techniques. So, your mileage may vary but it’s still a great resource.