To deepen the topics I would also still "The Princeton Review - Cracking the TOEFL" pick me. This book provides additional exercises and especially practice tests on CD-ROM again. The more practice tests, all the better!
The strategy: I would recommend everyone to do at the beginning once a practice test to classify your skills and current status. Depending on how your result fails to focus on the areas particularly where you have cut weaker. Approximately 1 week before the test, you should then make the rest of practice tests to get a feel for the test situation.
By the way: It is enough perfectly, the books used to buy!
A very important TIP:
This advice really close to my heart, as it itself really annoys me. Power your test, please in any university / college or school! Please go necessarily to a professional IT centers that specialize in such computer tests. Even if you have to go on it - the money, I would invest in any case! In my TOEFL I was namely in Nuremberg in the Languages College and the test conditions were super bad! There were far too many people in the room, there were no partition walls between the computers and the coordination was awful. So it was that the person next to me had a problem with the computer, while my test already launched! I have about 5 minutes of time lost at the beginning, because I was so distracted by the problems of my neighbors. They've got actually spoken beside me and ran my time! It's already nervous enough with such a test, because it does not need something like that! These 5 minutes you will have a major effect on my test result. It really annoys me - especially for the price you pay for this test!
Please go, please become a professional institute! I was then the GRE test namely near Frankfurt (Eschborn) - and there were no problems!