I found this website really calming while I was pregnant - lots of stories of different births, but all told really positively. http://tellmeagoodbirthstory.com You can get quite a lot of hypnotherapy downloads from Amazon (I tried the Maggie Howell one, which was also calming), but if you have time from all reports try to find an a actual hypnobirthing course to get the maximum effect.
I used the natal hypnotherapy one from Amazon mentioned for my DDs. With DS (first birth) I was in agony and freaking out, I was even screaming during contractions in the corridor and had to have pethidine. With my DDs I was calm, I felt in control and while it still hurt it was manageable, I just had gas and air for the pushing stage. I'd recommend it to anyone.