Looks like the Heron had some bad meat for dinner last night.
What it's about... Being out on the river with the sound of a running stream with the occasional splash of a trout hitting the water after charging after an emerging insect. Spotting rising trout and figuring out what they are taking. Sometimes you can figure it out right away and other times it might take a few hours. Mostly for me it's about casting. I love to see how far I can cast my 5wt line. Even hooking into a fish at 100 feet away is exciting. You don't even have to land the thing, just knowing that you fooled him at that distance is enough to get your adrenaline going.
This site does have a hatch chart with a link to pictures as well as a general time frame in which those insects are expected to hatch.
North Eastern Fly Fishing Forums NEFF Hatch Chart!
As far as being productive from March - June. That you'll have to pay attention to the threads for. Watch what people have been posting. Normally the south eastern rivers run a little earlier than the northern rivers due to temperatures.
Feel free to ask any more questions right here.