proper age - AT LEAST 12 months and a weight of 350 grams, more is preferred.
Brumation - IS necessary in most dragons, for some young ones it is not vital, but it always increases fertility.
Breeding dragons is a lot of work... you need to be prepared to spend massive amounts of money on food for hatchlings, and feed and mist them 3x a day, are you SURE you want to do it? make sure your animals aren't related (if you got them from a pet store, then they most likely are related) and get a vet to check for parasites. Also your female(s) must be not just of average health, but superior...
SEE THIS WEBSITE:
http://www.dragonsbynature.com/breedinginfo.htm
-Drew