I would suggest looking into a book that powder shooters use.....this is what I did. You can change some headers over or take them away all together....like Powder used....the sheets have sections for FPS #'s, bullet type, weight, brand....all this can flow pretty easy over to the fire arm forms.
After I get that all sorted and I know what pellet works in what gun and at what distances I will make a tabbed section in a school type binder.....they do make "tacticool" binders but I am a cheap bastage and will not pay for that to look cool.
Then you can make a type of shot card....in the air gun world think what a field target guy has....a note card with ranges, scope dope.....that kind of thing.....then you know what you need at what distances....and what pellet to choose.