Flowers in the spring, Foraging all year long

Above are a few examples of the local foliage and flowers out in early spring here.
(Top to bottom:  Oregon Grape Holly (Mahonia), red and white Trillium, Daffodil, Forsythia, Myrtle, White and Blue Violets mixed with unopened Lilly of the Valley, and Trout Lilly.)  (The violet flowers and Trout Lilly leaves and bulbs are quite tasty. )
To learn more about foraging (In the north eastern part of the U.S. especially)  my favorite books on the subject are as follows:
 -'Nature's Garden' by Samuel Thayer.  It has very clear,extensive photography for identifying the plants along with text regarding description, range and habitat, harvest and preparation.  Another of his books titled 'The Forager's Harvest' has the same format with different plants.  I'm glad I purchased both, but of the two, 'Nature's Garden' has more information and photos of interest.
-'Edible Wild Plants', Eastern/Central North America, by Lee Allen Peterson.  This has very detailed drawings and concise information for identification as well as usage.  There are symbols on the side for quick reference to various uses, such as salads or teas.  Included for side by side comparison are also drawings (and information) on poisonous plants, signified with a skull and crossbones symbol next to it.
-These two books above compliment one another, and thus far are my favorites.  The clear photos and detailed drawings , and the text in different forms for cross reference of information. I would want to take both of these books to more clearly  identify prospective plant snacks.  A word to the wise: before eating any wild plants, be 100% SURE of what it is; sometimes the difference between delicious and poisonous is very slight.
-'Edible and Medicinal Plants', by Steve Brill and Evelyn Dean.  I enjoyed reading the information in this book, but it would not be one of the books I would take into the field to ID plants.  There are also attractive, artistic drawings of plants throughout the book which give a general idea of what a plant looks like, but not detailed enough for clear identification.
-'Northeast Foraging', by Leda Meredith.  It is a very nice read, the photos are very clear and helpful, and although it doesn't include as many plants as the books above, it is nice to get another perspective on the plant's usage. One thing I take exception to in this book:  Even mentioning Ginkgo nuts!  Besides being poisonous raw...The smell of the fruit is SO disgusting...words can't really describe.  For the record though: the non-fruiting male trees are very cool looking.  One of my favorites.
-'Medicinal Herbs, A Beginner's Guide", by Rosemary Gladstar.  Ok, This isn't a foraging book per say, but it contains uses/recipes for some of those plants you have successfully foraged, as well as a few of the herbs you may have growing in your garden already.
-Why forage?  For the free, organic, (check location found), nutrient dense, often very flavorful food!  And you never know when being able to find food in the wild (not to mention your own yard) may prove to be especially useful.
Enjoy!