I've listened to Derren Brown's Trick of the Mind audiobook thing about hypnotism, which seems like a good introduction. It gives examples for very basic hypnosis techniques, and a little bit on how you can take it further, and really helps to understand what hypnosis actually is, but there must be some great in depth sources out there. I'm also interested in those Snap inductions you see people doing, there are always warnings about those however, are they particularly related to the slower kind of inductions, are there good places to learn these? Any professional hypnotists out there?