Stalking the Wild Asparagus by Euell Gibbons. A lot of people today don't remember Euell Gibbons, or they only remember him from the 70's cereal commercial, which is a shame. He was THE wild foods expert, and his writing is highly entertaining and informative. I highly recomend that you try at least one of his books. Also in print are his Stalking the Healthful Herbs and Stalking the Blue-Eyed Scallop. Out of print but worth a search are his Beachcomber's Handbook, Handbook of Edible Wild Plants, and Stalking the Good Life.
Peterson's A Field Guide to Animal Tracks by Olaus J. Murie. A very nicely done guide to the tracks and signs of North American mammals.
Peterson's Beetles : A Field Guide to the Beetles of North America is a great field guide for quick identification of beetle families. A nice first guide, but if you are a SERIOUS beetle nut you may want the MUCH more extensive (and expensive)...