Head downhill far enough, and you'll find a river with fish in it. Squirrels are everywhere, Rabbits too. Acorns are usually bitter in the East, need to be shelled, boiled and pour off the water. twice is better. If there are acrons on the ground, it means Squirrels aren't far off. there is an old saying, "Leave the acorns, eat the squirrels", or in other words , "Eat the Eaters".
I'm more familiar with the Appalachains in VA, MD, W VA and PA. I don't know how far North you mean, by Northern Appalachains. In the area I am familiar with, the Appalachains have a lot to offer, lots of flora and fauna. Plenty of water, in most places, most seasons, this year we were in a drought in our region, I haven't heard any first hand accounts of wehter or not water sources were in jeopardy, but I'd check on it before heading out.
Head downhill, 99 times out of 100 you will get your feet wet. Once your feet are wet, head downstream and you will eventually run into a river. In fact, by my experience, it would be difficult to avoid water, unless you just ran the ridges at all times.
You will have to research the edible plants. I know of only one real good way to teach/learn edibles, go out with someone who knows them well, and get your hands on them. Peterson's would be the next best bet, as was mentioned, but, it's still nice to have someone verify the plant for you, in the field, unless you absolutley trust yourself.
Shelters should be no problem, water should be no problem. Fire would only be a problem if it's been raining for many days straight, but tinder is pretty much everywhere, during most , if not all seasons.