This is neither a standard biography nor bibliography, but rather a compendium of all manner of bits and pieces of minutiae and obscure material about or related to Howard. There are several autobiographical pieces, biographical pieces by H.P. Lovecraft and others, letters, fan magazine pieces, juvenilia, book and magazine covers, family photographs, cartoons, lists of stories and series, obituaries, etc., etc. It's an amazing amount of information, but not terribly well organized or easy to readily access if you're looking for one bit in particular. Some of the material is really fascinating, particularly for Conan fans or for those interested in the pulp magazine era.
For a long time this was the standard by which all other works on Howard were measured. It is still useful, although the bibliography would have to be "greatly" expanded to bring it up to date. It's still full of interesting tidbits, and is a collector's item. I doubt you'd get a copy cheap.