I know this site mostly deals with non-BDSM hypnosis, but I'm sure there are a few kinksters around here. ;) I wrote an e-book called "Introduction to self-bondage"- it's not terribly long, but I daresay it's got some useful advice. If you'd like a copy, send me a message with your email and I'll send it to you. The only thing I ask in return is that you post a quick review on Amazon. :)
Thanks! :)