What you get is up to you. Go to caprinesupply.com and order their catalog. It contains a wealth of information. If you go the agricultural extension office in your area they will have some bulletins meant for 4Hers. They are inexpensive and helpful. You might go onto amazon.com and see what they have on books about dairy goats. I have found the Storey books to be helpful and they are not expensive. Contact the American Dairy Goat Association. I don't remember the PO box but they are in Spindale, NC 28160 and that ought to be close enough. Ask them to send you some literature.
If you buy a milking doe, taste the milk. Some goats give great tasting milk and some don't. Just don't try to have a single goat. Goats need a companion more than most other livestock.