How interesting. Zacs has given you a good start. Unfortunately I don't know anything but I would love to know how you get on. I used to work in adult education and always enjoyed it very much. I was surprised when they paid me at the end of the term because I liked doing it. It is very rewarding to teach adults.
The first port of call should be your local college or university. Some accredit courses but they may only do so in certain subjects. Try looking at the local university's website and see if you can find out more info there.
The next step is to search for the accreditors of your subject. eg The British Council accreidt English Language courses but for general information you could try the British Accreditation Council
Thanks guys - so busy writing the course I forgot to look back to see if I had any feedback - Love the idea of running a course on how to run a course LOl
AND Thanks for the support - it may take a fair few months - but I will post back occasionally and let you know how I get on xx