Mushrooms Demystified by David Arora (Berkeley: Ten Speed Press), 1986

At nearly 1,000 pages this is for the serious mushroom hunter.

All That the Rain Promises and More . . . by David Arora (Berkeley: Ten Speed Press), 1991

This pocket guide describes some 200 of the most common Western mushrooms.  You will still need more than just a book to identify much beyond the distinctive chanterelle.