I agree with what Baptism says.
In addition, you should milk twice a day, as close to 12 hours apart as possible, and stick with whatever schedule you pick! Don't let a doe go past her milking time - not only will it cause her to dry up, it is very painful for her.
In my opinion Nubians have the best and sweetest milk of all the breeds. Also, they don't usually give quite as much, so it won't overwhelm you with gallons and gallons of milk and you do have a chance of using it all. Their milk is high in butterfat, so if you get a cream seperator you could even make butter.
In addition to mastitis, goats also get "goat pox" sometimes. There will be little sores on the udder, and you may get little sores on your hands. A long time ago, when there were not so many life-saving vaccines as there are now, many many people died of smallpox. Usually though, only the men of the household would get it! That's because milking was considered "women's work" and the men would not do it. The women would get those little sores on their hands from the goats (goat pox) or cows (cow pox) and that would make them immune to smallpox!!! If your goat does get goat pox, it usually goes away in a week or so. You might still talk to the vet, but it is not as serious as mastitis.