First printings are the prestigious members of the first edition club, but remember any first edition is likely to be valuable. Hard cover books are, usually, more desired than paperbacks. So the next time you discover a dusty, maybe yellowed, book, you will be armed with the knowledge to identify its edition. If it is a first edition, snatch it and treasure it for the piece of history that it is (or, if you must, sell it for thousands of dollars). Happy book hunting!