This volume fills in a lot of the other material you are going to learn in class that was omitted from the first set. Specifically, Jason really expands the coverage of trig identities material. In this set, he has sections on the double angle, half angle, product-to-sum, sum-to-product, even/odd, and Pythagorean identities. There are also sections on solving trig equations and multiple sections on the law of sines and the law of cosines. All of the material is presented in the style of Jason's other DVD sets where is does a basic introduction of the topic and then works several example problems step-by-step. He rarely skips any steps and when he does, he always lets you know and it is usually because he has shown you how to do something several times and is trying to conserve space on the board.
If you get this, the original set, and the advanced algebra tutor you will learn about 90% of the material you will see in a trig or pre-calc class. The only big topics that you will not see are conic sections and the polar and parametric equations that some classes introduce you to (usually at the very end of the class). In none of Jason's DVDs has he ever covered everything that you get in every class. He touches on the main topics and the things you are most likely to see on a final exam.
I have reviewed several of Jason's DVDs because I have found them extremely helpful. They usually lay out the material in the same or similar order you will find things in the book. The step-by-step approach really makes you learn the material (and improve the "lower level" skills that you need at that level). It is NOT a substitute for going to class or doing homework. Jason does not pick your quiz or test problems, nor does he do examples of every problem you will see in the book. You have to go to class to get an idea of what your instructor focuses on. You should use this to prepare for class or reinforce the lecture topics, and learn strategies for solving the problems. If you use it that way, you will definitely know the material well and get a good grade.
The other thing to keep in mind is your learning style. This is a videotaped lecture of a guy in front of a whiteboard doing problems. If you can learn from that kind of thing, it is the best investment you can make. If you have to be able to interact with a real person and ask questions, you are probably going to need to invest in an actual tutor.