Most maples provide the same edible contributions... sap, seeds, inner bark and sweet young leaves. Syrup of course is the most famous food to come from maple syrup but luck for us they can provide even more than that. First step is identifying the Maple Trees! So let get right down to it.
Instead of lengthy written descriptions here is a series of picture of various maple tree species you may encounter.
Silver Maple Leaf. Photo Credit: Steve Nix/ About.com
There are other Maple species out there but I think you get the idea of what to look for from the pictures above when trying to identify a Maple tree.
You can make maple syrup from all maples but some will produce more than others. Do not think that you are restricted to only sugar maples. Note Box Elder does not look like most maple leaves but is actually one of the best sources of sap for making syrup. Here is a picture of its distinctive leaf.
The winged seeds of maples are also edible. Removed the wings and then parch, roast or boil them. You have probably seen the two seed pairs of maple seeds helicoptering down to the ground before. The seeds can be eaten raw but I suggest leaching them first to reduce the bitterness. It is easiest to collect the seeds while still on the tree. Peel wing and cut the end of the bump off and squeeze out the seed. To roast seeds put them in a 350 F oven for 8-10 minutes. Roasted or dry seeds can be ground into flour.
I view this more as a last resort food but the inner bark called the cambium layer can also be eaten. Raw, boiled or roasted. Your choice.
Another edible that is available from the Maple is young leaves. Again they suck in both taste and nutrition but in a survival situation beggars can't be choosers.
Eat raw or cooked.