I didn't have a birth plan for the first time round except "No epidural" because I have a fear of spinal anaesthesia. I should have had a BIT MORE of a plan as I ended up going through the basics while pushing my son out after a remarkably speedy first stage. Anyway, the most important things are:
Anything you absolutely do not want, and reasons (phobias etc). For instance, if you only want female practitioners to carry out internal exams.
Your preferred pain relief, if any
Whether you want the baby delivered onto you or cleaned up and then passed over
Who is to cut the cord
Feeding method - if you're breastfeeding, it's quite important to feed the baby asap after delivery. They will latch the baby on for you.
Whether you want a managed or natural third stage. Mansged means they give you an injection of syntometrine to force contractions, natural means you do it yourself. I had a managed third stage because I'm high risk for postpartum haemorrhage. I will have a managed third stage again with this baby. If there's no medical reason to have one, don't feel obliged though.
That's the most important stuff. Anything else will require your written consent, so you will have a chance to think about it. There's no point being too specific because every labour and birth is different. Some women are most comfortable labouring on their back (but it's not very common, I was comfiest on my knees, which is standard). Be prepared for labour to be absolutely NOTHING like you anticipated!
Things can happen at a moment's notice, so educate yourself and your partner NOW about interventions: artificial membrane rupture, various methods of induction, ventouse, forceps and caesarean delivery. If they're gabbing off the reasons why whilst proferring a consent form, you might feel utterly bewildered. Less so, if you learn about them now. Be aware that any chemical pain relief can slow labour right down.
The only thing I can see a problem is that when the contractions are strongest is just before you go into transition and start to need to push, so you will need to be checked out at some point when you're in MUCH (and likely continuous) PAIN. They will keep an eye on your baby's heartbeat throughout with a handheld doppler, and also do you obs (BP, temperature and pulse) which can be BLOODY ANNOYING mid-contraction, but it's very important to keep an eye on you and the baby's welfare throughout.
If the baby's not breathing, he or she will be rescuscitated as a matter of priority, then given to you.
I'm due April 11th. Having a homebirth, so it should be quite different to my first birth!