Ive got a place for midwifery next year. I volunteered at a local hospital but the age restricitions are a pain.
I would steer well clear of doing nursery work, and working on childrens ward if i were you, as they wont be seen as anything to do with the course.
If you write to the hospital then just say you're wanting to start a midwifery course and would like to get some experience. Also, you can go on different wards, such as ante-natal, maternity, delivery suite and even gynae.
And the classes are a good idea too, like what oh_eight said. Theres ante natal classes, and breastfeeding classes etc. Or check where your nearest baby cafe is and contact them. You can then get chatting to the mums about their experiences etc (dont ask a long list of questions though!!)
Hope some of that helps
xx