This book is a classic and has tons of great information for use with any D&D campaign -- even modern ones. You would have to change the stat blocks some, I guess, but the write-ups of the gods and goddesses and other creatures as well as the various planes of existence could be taken pretty much as preinted and used for any edition of D&D, or heck any fantasy game.

The scan itself is decent... it's clearly a scan of an old book, but the quality is about as good as one could possibly expect. I was rather pleased with it. Well worth the price.