Walls and Ceilings - Drywall Seams/Tapers

I am about to attempt some drywalling for the first time and have a question about seams at inside corners, especially seams at the wall/ceiling intersection. I assume that it is desirable to have the untapered edges of drywall meet at these points -- true? Is there any particular difficulty in taping and mudding a tapered/tapered or a tapered/untapered seam in these corners? Thanks!

The tapered or rolled edge should always be together. For example you have a wall that is 7 feet tall and 8 feet long. You put the first sheet on the floor and attatch to wall. You take your second sheet, cut 12 inches off, and stack on top of the first one with the rolled edge down and the cut edge up towards the ceiling. Whatever is left in the corners after that you finish. What I'm saying is that you worry first about the rolled edges being together and second about what ends up in the corners. Now to answer your question, it is actually easier to finish a tapered edge in a corner because your fill coats fill in the taper. You are going to get tapered edges in the corners and not tapered edges. Just do the best you can with what you got.