Talking to many deck builders over the years we have found that stair construction is almost universally considered the most difficult part of building a deck.  In order to layout the stairs you need to measure the exact height of the deck from the top of the decking to the location where the stairs are going to land on the ground.  You can input this number into our stair calculator on decks.com to determine how many stairs you will need and at what specific riser height they will need to be built.  The calculator will provide you with all the vital information necessary to cut your stringers.  In cases where the stairs can land wherever necessary it should be easy to move forward.  If you are trying to land on a specific position like the edge of a patio you may need to manipulate your stair configuration or change the run distance by adding or subtracting landings or shifting the starting position for the stairs.