As university chemistry student, I was more than elated to stumble across this jewel... http://www.ochem4free.com Basically, two people decided to co-author a fully-featured, three-volume, organic chemistry textbook. All you have to do is register (it's free), and you will immediately be given access to a part of the site where you can download the textbook in the form of individual .PDF files (each chapter in the textbook is a separate PDF file). I am about 25% of the way through this textbook, and I have to tell you: I love it! I have yet to even take organic chemistry at my university, but I already am understanding it. This textbook is awesome. Each section in the chapters end with a "try-it-on-your-own" summery questions/problems. I hope you will find this textbook as useful as I have.