My good friend Kathy has just published an eBook which covers the reading section of the TOEFL. You can buy it on Amazon right here. The book devotes a chapter to each reading question type and includes strategies to solve them, a list of "traps" used by ETS to trick students, and a ton of sample questions to illustrate these things. It concludes with a complete sample reading test. Unlike a lot of popular textbooks from major publishers, this one actually reflects the current state of the TOEFL. I recommend it!