How long do I have to wait after using my oven for dairy to use for meat?
There is no need to wait, and an oven can be used for meaty right after use for dairy.
However, if both the dairy and the meaty foods are moist, the oven should be cleaned and left on at a high temperature between uses. For these cases it is ideal to wait a 24 hour period in between uses.
Concerning covered foods, see Shulchan Aruch, Yoreh De’ah 108:1; Ksav Sofer 54; Igros Moshe Yoreh De’ah 3:10; concerning dry foods, see Igros Moshe Yoreh De’ah 1:40 (and 1:59, concerning baking a challah) based on Pischei Teshuvah 92:6.