Hi Plums,
I have been looking into making goats milk soap too. I have now gathered all the equipment and ingredients, and am ready to have a try at making it. I got a book, just from amazon
http://www.amazon.co.uk/Milk-Soapmaking-Simple-Buttermilk-Coconut/dp/0938497456/ref=sr_1_1?ie=UTF8&s=books&qid=1271886570&sr=1-1I did find it quite hard to find some of the ingredients, and did have to resort to the internet, though I avoided ebay as I found it expensive, and full of pour and mold soap kits, which is not what you want.
You do need to register and obtain your certificate if you want to sell your produce, but if you want to make it for your own use, or to give a few bars as presents, you don't need to.
I know this lady too
http://www.carolmcmillansoaps.co.uk/ as she bought two of my goats for more milk. Her website is quite handy, and her phone number is on the site. Oh and her workshop is fantastic!
If I have enough free time this weekend, I might try a batch of soap actually.
Beth