These next few months are nymphcentric. To gain a little more understanding of nymphs start taking some samples. Pretty easily done with a 3'x4' screen sieve. Caddis, stoneflies, mayflies, midges, craneflies, fishflies, leeches and aquatic worms can all be found within a few hours if you put your time in.
You don't have to turn into a Latin spewing geek to understand the basics of entomology. What you do need to do is transfer your knowledge to patterns and techniques. Quite simple really. Grab the Thomas Ames 'Hatch Guide for New England Streams' for a complete explanation on what goes on around here.
Better than wondering what the hell are those fish eating.