Another vote for Clare Byam-Cook.
I'd had a rotten time trying to breastfeeding my first. The midwives really hadn't helped, the NCT telephone helpline was next to useless sadly and after 2 weeks of trying I was ready to quit. She was my last call and should have been my first. It took her 20 minutes.
I hate the complaints of 'she's not even properly trained' blah blah blah. Perhaps not, but she has been teaching mothers to breastfeed for donkeys years and I'd trust her a whole lot more than someone who successfully breastfed themselves (and thus think it'll be easy for everyone!) and did a short course in it.
She polarises opinion because she is sensible. She doesn't believe that breast is best in all cases. She does advocate using formula if you're short of milk, especially in the witching hours. She doesn't believe that formula milk is the spawn of satan and she never, ever makes a mum feel crap or guilty.
And with that in mind. Best of luck with the feeding. When it works it's great. But if it doesn't, don't fret, it's not the be all and end all. Some babies will feed for Britain, but some are just tricksy no matter how hard you try.