I have been studying to take my first Toefl Test and this book has helped me a lot. It is very organized and easy to understand. I could have even studied by myself, although I have preferred to enroll myself at a Toefl preparation course - just to get a teacher's help. Fortunately, the language school did not demand me to buy the material they use (from another publishing). Anyway, after studying with my Delta book, I used their material to try a new choice, but it was complicated, hard to find the tracks on the CDs and it really required the teacher's help, sometimes the staff's. So if you intend to study on your own or not having difficulties even having help from a school, Delta is the best choice. One tip: buy the material with text and audio CDs. Without the CDs, you won't be able to practice the listening part, which is said to be the hardest one. Good luck!