First thing to do is set the film speed. For starters just half the box recommended speed. (HP5+ says 400 and so it will be set at 200) Look thru the eye piece and point it at some tone then pull the trigger. There will be a red (?) number in the housing or maybe it is a graph with a needle. If you set that number to the zone V mark that is where the tone should be in the neg and in the print. In use what you want to do is locate where you want to have the shadow detail. Some say this is Zone III and some place this value on Zone IV. Say you decide that Zone III is for you put that number on the Zone III mark on the decal. That will determine your exposure. See how the shutter speeds and f:stops line up? Now read what you think is the tone in the highlight where you want detail. That is zone VII. Are there 5 stops there in f:stops? If so, development is normal if there are 4, then development is +1 and if there are 6 then a -1 development is indicated. That is the skinny.