Putting in new hardwood flooring what is the proper procedure for using an electric jam saw?

First, remove the door from the jamb. Then, with your jamb saw handy, take a piece of scrap of the floor you intend to install (use a scrap piece because the blade of the saw may scratch the piece while your adjusting your height) and put the scrap piece against the door jamg. Take your jamb saw, and adjust your height according to the pice of the scrap. It depnds on what type of jamb say your using. With the kind that looks like a circular saw with the blade mounted horizontally, and the motor on top of the blade, you can make your adjustment and remove the scrap piece and make your cut. The blades on this type of jamb saw tend to be much thicker, so when you adjust your height, take that into consideration, as well as the installation method you plan to use (glue down, nail down, or floating) because each method has a different height depending on what's beneath the wood. So, take into consideration what's under the wood (glued with a 5/32 inch trowel or nailed with nothing underneath it, floated with a 6 mil polyethelene and a foam pad? Is it being installed over concrete that has been sealed first with a good polyurethane sealer like Bostik's MVP with a 5/32" trowel - then to be glued with another 5/32" trowel = 5/16"). If you're using the kind of jamb saw that looks like it was converted from a 4" grinder, or like the Bosch that reciprocates, you'll need to keep the scrap piece against the jamb so you get a straight cut. Remember to take into consideration what's underneath your wood, and the thickness of the blade so you don't have too much of a gap between the bottom of the cut jamb and the top of the wood. Be sure to not make it too tight though, or you'll have a real tough time installing it and it won't have enough room to "breathe"...wood expands and contracts so be sure to leave between 1/8" to 1/2" expansion gap all around your room, including under the door jamb. You only have to go deep enough to not see any cuts or ends of the wood flooring underneath the door casing (molding). Also, check the power of your motor, because if you have a smaller motor, and you keep trying to cut too deep (into the 2x4 framing), you'll burn out your motor in no time.