What about The Forager's Harvest: A Guide to Identifying, Harvesting, and Preparing Edible Wild Plants by Samuel Thayer. It's not the most comprehensive book, but it has really nice pictures and it tells you exactly how to prepare each thing.
Old Sarge, I flipped through it at the library and then checked for it online. I think it's out of print but there are a lot of copies available for around $10. Amazon.com has a lot.
Checked Amazon today and found new copies for..........now get this.......$216.00, used ones from $39.97. Think I will be buying used this time! Maybe I'll wait until the prices come down a bit.