There are almost no drugs that are licensed for goats, but sheep medicines are usually used, as both species get similar diseases. Sometimes however the dosage is different, for example with wormers you would use 1.5 to 1.8 times the sheep dose for goats.
I would say a good basic goats veterinary book will also list the types of medicines you will need, I find that "The Goatkeeper's Veterinary Book" by Peter Dunn (4th edition) is more than adequate (but I also have sheep books about and always cross reference to them as well).
The basic ones are:
Wormers (always discuss with the vet which ones to use after faecal egg count, as most of them cannot be used at all during lactation)
Vaccines (the important one is Lambivac, usual sheep dose every six months against clostridial diseases and also includes enterotoxaemia)
Antibiotic - again only on prescription from the vet, you will need to know the weight of your goat
I also do not buy medicines over the internet, get (also for the sheep) individual amounts for specific animals (often in a syringe - but have so far not been stopped by the police!). That way it is also a lot cheaper. Vaccines (Lambivac) can be purchased from merchants, and you will need to buy a 25 animal dose bottle minimum, as that's the smallest one you can get...
My vet is very keen on goats and I find that helps quite a lot.