That if you are terrified beforehand it really won't be as bad as you think, but anxiety will make it seem worse. My first baby I was utterly terrified, sobbing all the way to the hospital, crying when I checked in to the labour ward, but it really wasn't as bad as I anticipated, despite it being a traumatic birth and long labour, it really was nothing like I imagined.
Equipped with this knowledge the second and third tomes round I was far more relaxed and my births were both amazing, joyful experiences with no need for any pain relief at all.
That if you really do listen to your body, you will know what to do. Let your instincts take over, don't stay in your head.
That water of every kind helps. Drink it, bath in it, stand under the shower.
Standing up, walking around, really does help. Gravity innit.
That anyone talking in the late stages of labour is really irritating. Put headphones and block them out.
That even if breastfeeding is really bloody hard and seems impossible, for the overwhelming majority of women it is possible and does get better/easier. I gave up within hours with my first two, and believed I couldn't breastfeed.Having educated myself about how extremely rare it is to not be able to brestfeed, with my third I was utterly determined. I read every book on breastfeeding, asked friends who had breastfed for their insight, and stuck at it. It was ridiculously hard work, my daughter wouldn't latch until she was 12 weeks old, so I pumped what seemed like constantly, but we bloody got there and she breastfed until she was 3.
There is nothing more powerful than a new mother. You will find strength you never knew you had and then some, but my god, you will cry. Don't be afraid of a proper cry, you'll need it.