Never seen a book on Dapping, don't believe there is one? But I'll share what I know with pleasure. First you need a long rod, 15' is good. Next you need to hire a boat on a goodly Lough, Corrib/Mask being fave. Timing is particularly imp-mayfly time being best.
You need to buy a thing called a blow line. It's a flossy thing, bit like dubbing and quite broad to catch the wind. Thinks it's only 'flossy' for 15-20 feet.
Ok...attatch your bug and hold the rod high and let wind (oh, windy day only) take the fly (bushy) and just let it all kinda float away on the wind. It will land somewhere with gentleness. Once landed flick it occasionally to make it fly again...it's a real hoot. Trout go mad for this approach if all is good. Soon as you see the lot sail out and drift in the wind you will know instinctively what to do next-you will!
If you want to enter the top league of Dappers you need to build yourself a 'Mayfly Box' and catch live ones to be used at your discretion. Two at once is popular-if one dies...
Also you can play the same game with Daddies, mmm.
Irish showed me, like them real fun