How do I put up a roof ladder?
Ok Walker, here's the scoop. beg, borrow or rent two extension ladders, ladder jacks and a walking pick. (wide plank that fits into ladder jacks). This will form a stable staging a few of feet below the roof soffit. Calculate the length of the roof and adjust your roof ladder accordingly. TIE OFF the rungs of the roof ladder, if using an extension ladder, so it cannot disconnect from the adjustable height locking hooks. Lean it up against your pick, climb up on the pick and carefully drag the roof ladder up and over the pick to the roof. The other advantage of using a pick is that you can work along several feet of the roof, moving your roof ladder as you go.  Most picks are 10 to 18 feet in length and can be equipped with a safety railing.  Check out your local rental center.  Be Safe. 

Pics and procedures for using ladder jacks and staging (picks): http://www.ehow.com/about_5046018_ladder-jack.html