As I find some example, I see when we want to create a camera class for D3D or 3rd person shooting, it may use Quaternion, also, we can use D3DVector only to perform rotate the camera? What is the different between them? Also, I don't really understand the steps or concept about rotate camera in 3rd person shooting, but I understand the concept in walk or left/right or up down concept, the rotate camera concept looks like difficult, would you mind to tell me more? Thx so much!

No specific advice, just a few general suggestions. First, forget about quaternions; you won't get much out of them unless you already have a good understanding of matrices and rotations in general. Study some basic trig (if you haven't already), and read everything you can get your hands on about vectors and matrices. I also recommend this book as a good starting point.

From your recommended book, does it contain the concept or the tutorial about camera ? such as rotate?