From my generation just about anything by Elmer Keith, Skeeter Skelton, Jeff Cooper, Bill Jordan, Massad Ayoob, Jack O'Conner are all great writers to start with. I also like Small Arms of the World, Standard Catalog of Smith and Wessson, and Colt-An American Heritage.
His website is pretty good, tooI'm reading Jack Hinson's One Man War. It's a good one about a Confederate sharpshooter.
This website is pretty good, tooIf you like revolvers, check out Grant Cunningham.