Good post!
I have about 70-80 books in my reference library. That does not include magzines such asTactical Rifle, Precision Shooting and Accurate Rifle. I have a number of the usual suspects such as various volumes of Gun Digest, Cartridges of the World and the firearms disassembly/assembly books. I also have other, much more difficult to find books such as the older Handloader's Digest volumes, Gun Digest Treasury Volumes. I also have many loading manuals from Lyman, Hornady, Speer, Sierra, etc. This includes many of the older manuals that list obsolete powders and bullets that I use often as reference material. I also have bullet casting reference books such as the Lyman manuals, The Art of Bullet Casting from Wolfe Publishing, and others. I have books on big bore revolvers such as Bowen's The Custom Revolver and Taffin's books. I some of Elmer Keith's work, as well as books by Capstick on African hunting. I also have several gunsmithing books for the 1911 pistols as well as for revolvers. One good book for reference on bolt action rifles is Bot Action Rifles, 4th Ed. by de hass and Van Zwoll. Another interesting, old book is Colt Automatic Pistols by Donald A. Bady, published 1973. This book goes through the pocket pistols, rimfires, baby pistols and the 1911.
I also have books on shotgunning, smallbore rifles, small game hunting, defensive shooting, social studies on guns and crime, military arms, both U.S. and foreign, etc. Basically, any area of the shooting sports that I've ever had an interest in, I've acquired books about.
Recommendations: Street Stoppers and Stopping Power by Marshall and Sanow. They are not the bible but they are interesting reading.
Standard Catalog of S&W, 2nd Edition.
75 Years of Crosman by DT Fletcher.
Airgun Hunting and Sport by Ron Robinson.
Old Gunsights by Nick Stroebel.
Old Riflescopes by Nick Stroebel.
The NRA Handloaders Guide 1969 Edition.
Gun Digest Treasury The Best from 20 Years of Gun Digest
The Art of Bullet Casting -- From Handloader and Rifle Magazine 1966-1981.
If you have a specific area of interest, let me know and I'll get you some titles.