Wikipedia has a fairly comprehensive description of craniosacral. It's a good place to start.

http://en.wikipedia.org/wiki/Craniosacral_therapy

Growing up as a skeptical New Englander (and ending up in mysty-bisty California) I carry with me a fairly substantial load of disbelief in anything that cannot be measured. So I've approached c-s with caution. My own jury is still out, but as I mentioned previously, I'm doing quite well and perhaps c-s is part of that. At the least it's a treatment that doesn't have to cope with that old Beowulf, the bloodbrainbarricade.