using scan tool to help with tuning ?'s

I am still pretty new to EFILive and although I have made a few tunes I am still kinda in the dark about useing scan tool to help with tuning. I know how to select what PID's I want and how to record data but I am not sure how to correlate it and tuning. How do I know where to add fuel or timing or boost? Whats the easiest way to set things up? Do you look at the gauge panel the graph or just the data page? How do you run your logs ie: just driveing around or full throttle blast from stop to wherever? I also dont understand the maps at all can someone explain them to me?
I know I am missing a big part of this and I know this will help out emensly when i tune so any help is appreciated. THANKS

Randy