Are you a regitered charity?
All of this is worth so much more if you are. Ask you accountant about how to harness gift aid. Also re your online donations, again, if you set this up right, you get back the gift aid slice of the tax too.
go and give a £1 to someone on http://www.justgiving.com/ and you can see you to bring in the gift aid requirements.
I'm new on here and have not had chance to introduce myself but saw your post and wondered if I could help. I've been involved with a child care business for the last ten years which has recently closed (due to my mothers retirement!). We have various contacts for insurance etc if they would help. Also have all sorts of toys and equipment that could be useful to you!
If I can help just let me know . . it sounds like a great project!