Have a look at the tutorial, that covers pretty well all of it. Alter Eagle Site look at Owner tutorials
You're lucky of you've managed to find a crown with the spring angle that matches the saw stops...
Mark out the crown at your corners so you're sure to have the right rise & run (which gives you the spring angle) and you'll find that you'll most likely need to carry a few shims with you in older buildings, to shim out the corners at the joints... it's all in the tutorial. Also if you cope you'll find you'll get a better fit.