Berries, walnuts, some greens, a few shroomers and, most recently Bergamot.
I don't really do things out of people's yards, but once I started looking around I've found things everywhere. I also like foraging through abandoned garden plots at the community garden (actually abandoned, like for months).
To learn mushrooms, we've joined a local mushroom group that has forays in the spring, summer and fall, and that has been very useful. If you want to eat anything aside from Morels, you really ought to learn mushrooms in general.
Especially since you're east of the rockies, look at Sam Thayer's books. Wonderful, wonderful books.
I just found a beautiful hazel right outside my office, speaking of.