Treasure Room - Where you store you gold, where your creatures go to get there pay, this is one of the most important rooms.
Lair - Where ur creatures Sleep.
Hatchery - Where ur creatures Go to feed, this is very important coz they need food 2 live!
Training Room - Where ur creatures go to train and get there levels up.
Library - This is were some creatures go 2 learn new spells and rooms for u, warlocks and wizard work best in library, ur dragons will try and go in there but dont let them, they are better when they are higher levels.