I've read (and I'm trying to practice this rule) that if the cut is going to be more than about 1/8" deep, then make it in more than one pass.
However this is not a hard and fast rule. #2 pine you might be able to go deeper like 1/4". White oak, probably no deeper than 1/8" at a pass, etc. Also depends a little bit on the type of bit and its cutting quality. A straight flute job will tend to pack the dust and chips a little bit behind the bit. An up-cut spiral tends to pull them out while a down-cut will try and pack them under the bit. However a down-cut will generally make neater edges on the dado so you make trade offs and maybe have to take more shallower passes.
I'm sure some of the guys like BobJ, Mike, Harry and the rest will chime in with good suggestions. They have a lot more time behind the trigger than I do. But I'm answering these sort of posts as a way of re-enforcing in my mind what I'm learning.