I have a hypno birthing CD. I found it infinitely helpful that there is an exercise on the CD that helps you understand how long 60 secs can be (the time to rest between your contractions). I have found that I can in fact get to a relatively relaxed, even meditative state in less than 60 secs, although that of course is NOW when I'm laying in bed or sitting quietly NOT as my baby is pushing against my cervix
I'm sure that will be more difficult!! But I enjoy the practice and I'm sure it will help.
The main thing that has helped me to feel more prepared to birth came from reading Ina Mae's "Guide to Childbirth" and really getting a strong sense that my body knows exactly how to get this baby out w/o much help from me. I am humbled by the fact that my body, w/o any support, very little understanding, and NO help from my frontal lobe has created, nurtured, and grown this baby. If my body can make this whole thing happen w/o my doing much but eating, sleeping, and exercising---I bet it can get this baby out.
Of course this is my positive minded mantra---Not an ignorant statement, I know that sometimes medical intervention is necessary and I am open to that, because in birth (as in life) things happen. But it has helped reduced my fears around thinking "How will I do this?" or "I can't do this" to just know that my body is very very wise.