Every situation is different in something like this, Skip. It is really impossible to give you much more than generalities.
If you set the molding in something square, like a saw or router table with a tall fence, the corner where the molding meets the wall is usually around a 38 degree angle.
Before you check this, read my posts of 1/9 and 2/9 on making backing strips out of 2x4 for mounting crown on walls and ceiling. The easiest way to do this is to go back to the index page (*** ****'s Message Board) then type Ctrl-f (both keys at the same time) then type the word crown into the box that appears. Keep clicking until you find the posts you are looking for. Use the same method except now your 2x4 backing must fit the wall/molding very accurately and be the exact angle. How you mount the backing depends on your cabinets.
Yes, a brad gun can be used. Don't try to nail too close to the ends of the molding. Cutting small biscuit slots and gluing the corners is the best way to get the corners to hold tightly. Glue and drill pilot holes for the brads if you have to.
For cutting instructions, at least for wall installations, go to www.zyworld.com/thewick/ then look for his links to useful sites. Steve's Place has the best cutting instructions. Sorry but I don't remember the address for Steve's site and if I go to my list I lose what I have already typed.
This really sounds like it is a job for an experienced pro. Putting crown on walls is tough and this will be a lot tougher.