There are a number of sites that I have found very useful over the years. Here are links to some of them.
Real Milk Campaign for Real Milk
Caprine Supply - The best nipples for baby goats and lot of other stuff. Including colored plastic chain collars.
Hoegger Supply - Supplies of all kinds
ADGA - American Dairy Goat Association
National Saanen Breeders Association
National Toggenburg Club
Onion Creek Ranch - This farm raises meat goats and has great information on goat health
Molly's Herbals - I have used her dewormer for years. My goats like it and it seems to work well.
I highly recommend this book to anyone wanting to learn about maintaining a healthy herd. It is available on Amazon.
Natural Goat Care by Pat Coleby