Hi, Lisa. There is a site with plenty of great instructions on how to cut crown. This is Steve's Place at www2.fwi.com/~kruny/ . You will want to cope inside corners and miter outside corners and the instructions are there for you.
By the way, this info has been put on the *** **** board many times before. You might want to do a search of the board page the next time to get a faster answer. You can search easily by starting at the top of the board page, typing ctrl-f, typing "crown" into the box that appears, and left clicking the mouse to show you all the previous references to the word in the thread titles.