So you roll up to this big stair set, not knowing what to do, if you don't want to eat pavement, read this guide.
The first thing you want to do is ollie it first, warm up a little bit. After that, make sure you are landing kickflips consistently.
Now, what your going to do is roll up to the stair set-if it is a long stair set, you want to give it that extra push-and pop, directly before your front wheels leave the ground.
After you pop, you are going to do that kickflip, and flick it, but nice and (moderately) slow. If you flip it too fast, you might not catch it right, and you might even land primo, or worse. So the board is spinning in midair, and you are hovering above it, keeping your shoulders straight. You want to get your feet back on that board once you see that sweet, sweet grip, and catch it. Usually, your feet go to the bolts themselves, but try to get your feet near them anyway.
Okay, so here you are, in the air, with your feet on the board, approaching the ground. Once you get close enough, you want to throw your feet down, and land it. Bend your knees at the landing, and roll away clean.
P.S. If you see that you are not going to make it, tap your feet down, or kick the board out, and land on your feet. It's called a BAIL.