Do plenty of research, find out all about EYFS and the childcare regulations.
Research your local community - are more childminders needed. What will make you different from anyone else. How much do local childminders charge. What is and is not included in that price.
Find out which schools do and don't have wrap around care facilities. All should have it but many don't really - so find out which ones don't have their own after-school club.
Look through the many messages on this site about Childminders... Ofsted Registration, Ofsted Inspections, EYFS etc.
Read the documents on the Ofsted website about Childminder Registration and Inspections.
Registration process itself can take 6 months, could take longer. Your local council Families Information Service will be your point of call (as bumbums said) with regard to getting the paperwork started.
Your NNEB will be quite old, so you will need additional training courses. Your council may have a policy of putting everyone on the ICP anyway... which will include things like Safeguarding. First Aid training is also required - again the council will tell you about that and may run the course - otherwise there are private providers like SJA.
There are costs involved in setting up... from the Health Check from your doctor (ask them how much they charge... it can be over £100), first aid kit, fire blanket and other home safety equipment plus of course toys and baby/toddler equipment.
Once registered there are costs of advertising... it can take a while to get your first mindees.