I am currently doing the hypnobabies home study course and I am loving it. While I haven't been through my birthing time yet, I have succesfully used it for various aches and pains of pregnancy, and stress relief. I also like that I can do it on my own schedule, though you do have to invest the time, and it is pretty comprehensive so far. I'm only about half way through... It does take a bare minimum of 6 weeks so that is something to consider. I choose it bc it had the home study option (reviews on hypnobirthing said ordering the course was useless without an instructor to teach it) and I found online it had better reviews between people who'd had experience with both. I also liked the "eyes open" technique bc I want to be able to move, speak, etc, in labor without breaking from my childbirth method:) Good luck with whatever you choose.
Oh.... another lady mentioned she used a few breathing techniques along with hypnosis when her o2 levels got a bit low in labor... so I plan to do a little side research on a few myself incase I need them:)