When you first register as a childminder, you are now required to take an "Introducation to Childminding Practice" course, which is part of the Cache Level 3 Certificate in Childminding Practice. Its a short course with a small assignment at the end, but covers the basics of all aspects childminding. You can do more if you wish, but I think this is the minimum. It certainly is in Darlington anyway, I am pretty sure it will be the same nationally.
Your local Early Years dept would be the best place to advise you on what the requirement is where you live. They should help you through the whole process.