I would say go for it and read his stuff.
Take some of it with a pinch of salt. If you have had any kind of experience with hallucinogens at all, then the stuff that stands true in the book, will become apparent.
I first started reading it before I had my first experience. After my experience, I went back to reading it, and all of a sudden, some his writings started to slap me in the face with prevalence.
There are some documentaries about him though, too. I recommend watching them also, to balance up your views.
I watched some films on him after I started reading, to see what he was really about. I was sad to learn that Cast. was such a fuck up towards the end of his life, but I still wanted to continue reading, merely because his works are regarded as classics. Then I had my experience, and it didn't matter that Castaneda had his own faults in his life.
He took a lot of his research from over two hundred books from real writings in the library, so a lot of what crops up in his books is in fact true.
Give it a read,
See you u like it,
8)