Some of my favourites are: Books by Vince Marinaro,and as Fly Fishing Texas states,"What The Trout Said " by Datus Proper, and "Trout" by Schweibert,
I also agree with Old Geyser, in his stated rememberance of what a guide told him "90 percent of what a trout eats is brown and fuzzy and about five-eights of an inch long.
Thats why my favourite flies are Hare and Coppers about size 12,and also what I call Brown Skungies,size 12,Hares fur body and tail,copper rib, gold beadhead,and a soft partridge hackle tied in front of the bead, and weighted. Regards, Highwood NZ