i respect weggiemum saying there's no way to prepare yourself... she's right of course, and it is unfortunately different for everybody and every baby, but at the same time there's a lot you can do! dont' panic! i was terrified about labour. now having just had my first baby the metaphor i always use is that of running a marathon - clearly it's going to be a hugely challenging, physical and mental, experience that will push you to your limits. but millions of people do do it! so you don't have to be terrified, but clearly it will help to be as prepared as you can even if you can never imagine til you've done it what it's going to take. physical techniques: start perineal massage if you haven't already, it will definitely help you streeeeeetttttch! and there's no way round that. think about birth positions, try them and if you can try to prepare by kneeling/squatting every day. squatting really works to get the baby moving - shortens the birth canal and gets gravity involved. i leant on a birth ball as well. look up breathing techniques and practise them. keep walking and make sure you are eating well you need the energy. make sure you've got food and drink packed you think you'll be able to digest during labour (i had all sorts of things on hand but actually it was hot, strong, sugary tea that kept me going). mentally: i did hypnotherapy which if nothing else will keep you occupied and calm before it all kicks off and got me through the first bit of labour with almost no fuss. you can still book to do this even 2 weeks before. i did the rest with gas and air; no idea if it actually killed any pain but giving me something to focus my breathing on helped! i also primal-screamed my lungs out at the difficult bits. god that felt good, i almost wish i could do that bit again!
re birth partners: i had my mum as my doula and i wouldn't have been able to do it without her. i know it's not always the way things work out (as you say, your hubby's not into it), but having somebody you trust and who knows you and the process of giving birth that can be by your side is very very useful as there are points you feel quite vulnerable or just knackered! (however equally i know women who wanted to be alone...) i would make sure your SIL knows what you want, what you like and don't and your plans (even if they change) so she can be 'on side' and give the right support. the best thing that anybody said to me when i was wailing 'i can't do this!' was, 'but you ARE doing it!' which was very true. i would NEVER be able to run a marathon, but i did manage to give birth, at home, epidural and tear free! you do it one contraction at a time my love, and you'll be fine and SO PROUD that you managed it. i bloody am!