sliverfrog - Thanks for that, interesting to know that your nanny has little formal SN training.
Your nanny sounds a bit like me... my SN experience is from doing 1:1 nannying/babysitting typically 3-5 hour sessions, helping on a playscheme, accompanying a family (3 children on autistic spectrum)on holiday.
I'm NNEB trained, so back in those days there was no part of the childcare course that covered special needs. Thus I'm self-taught via reading books (once I've read a book on SN, my local NAS branch gets it for their library).
I agree with you that it's the connection between the carer and the child that is important, rather than a piece of paper saying they have done X, Y, Z courses.
runikka - SNAP may be useful, but as sliverfrog has said, the nanny need not be specially trainned. So I would suggest trying to recruit yourself initially (much cheaper) and if you find that you are not get getting suitable candidates, then consider using an agency.
Childcare Vouchers can be used to pay a nanny, in England. The nanny needs to be registered with Ofsted under the Voluntary Ofsted Childcare Register (my renewal letter arrived this morning, cost from Sept 2008 for me to renew is £110).
You will find a lot of info in this section of mumsnet with regard to nanny recruitment, the tax/ni side of being a nanny employer, and about childcare vouchers. If you can't find the answer to something... start a new thread and I expect on the nanny employers, or a nanny themselves will be able to help you.
If you are able to get Direct Payments, then I would asking on the SN Board. You can also get help there for how to fill out the forms for things like Direct Payments, benefit entitlements etc.
Romy7 - what help do you need? Most of my Monday's are available at present. Let me know via e-mail.