Assuming you are using a moderate oven (around 350 F), you are baking.
You didn't say how you were cooking the chicken before when it was coming out dry. However, if the chicken was dry it was because it was overcooked. Chicken must be cooked to a minimum internal temperature of 161F. At that temperature, the meat is fully cooked and safe to eat. Cooking to a higher temperature will dry out the breasts.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan