All good advice here.
I used the 'Natal Hypnotherapy' CDs to relax and prepare pre-birth and then used the music (over and over and over) during labour and found that really worked for me. Might be worth a try if you are worried?
Otherwise, educate yourself as much as you can. Try some NCT classes or other ante-natal classes. It helps to meet and keep in touch with other people who are going through the same thing.
If you educate yourself about all the things that could happen in labour (without scaring yourself), pain relief options and so on, then you can make an informed birth plan but also be prepared to be flexible if something happens and you need to change your mind or deviate from the plan.
Have a birth partner who you trust (your OH, Mum, a doula) who knows what you want but will also look after YOU (wipe your face, get you drinks, whatever you need).
Make sure you go on the hospital tour, if they offer one. Knowing where to go on the day/night is very reassuring.
Do things that will make you feel better about yourself in the run up. I found that having a nice pedicure on my due date and a bikini wax was helpful. Reflexology is nice too.
As the due date gets closer, do everything you can to distract yourself and try to forget about it. Get some good books to read, go to the cinema, meet friends for coffee and lunch.
Good luck!