Since I don't know of a specific book off-hand, you should probably wait until you get here and check out a couple of bookstores.
Generally, there are few poisonous plants here to look out for. All the mushrooms except for the orange ones are non-poisonous. All berries except for crow berries (orange, round, and growing on the ground) are very good. We have high and lowbush cranberries, wild blueberries, raspberries in the interior, high bush salmonberries in south central and the coast, low bush salmonberries in the interior, moss berries and wild strawberries in the interior.
There are no poisonous plants such as poison oak, sumac, or ivy.
There are other plants that can be eaten or used as seasoning or flavoring that are too numerous to list here. Of course without pictures the info is pretty much worthless to you.
Also remember that "edible" and "good-to-eat" are two different definitions.
I've had the benefit living out in the bush with native folk of various regions for about 13 years now and going on food gathering excursions with them. The gf is Koyukon-Athabascan from a Yukon river community.
Enjoy your stay and spend lotsa money.