I'm partially baby-feverin' over here, and that means my brain wanders back to birth often. It doesn't hurt that oodles of my friends either have new babies or are pregnant too; birth and babies are all around me!
I had a normal natural birth with Lily, just as I had set out to do. There were a few things I would change (or rather one big thing--move the whole thing back home and out of the hospital), but overall it went well. I didn't take a birth class. I'm not even sure I finished a single childbirth book from start to finish. I had a doula and my husband present, but the former provided more support to the latter, I think, and I mostly kept to myself.
Here's my Short and Easy Guide to Childbirth (tm)
-Keep vocalizations low instead of high pitched
-Keep brow relaxed instead of furrowed
-Keep jaw relaxed instead of clenched
Add to that educating yourself on what's normal (say, going to 41 weeks and beyond), what to expect (oh, perhaps, transition), and what you might have to fight against (the typical cascade of interventions, for example), and you're good to go.