There are a few books out there. Can't recall titles to save my life. Go to the sports section of Boarders or Barnes and Nobile. They have books like that. Plus it's a bit funny to go to checkout at the registers with a book on guns or hunting and see the look on the face of the bleeding heart lberal working the counter
It still depends on condition, time of manufacture and markings. Get a copy of Fjestad's Blue book of gun values. Also reference Luger Tips by Michael Reese. Best way is to have an appraiser look at it.
Jim Zumbo, Craig Boddington, Ron Spomer and Wayne Van Zwoll are all solid contributers to the modern hunting literature. Through their gifts (both hunting and writing) they make us better hunters. Whether it is letting us learn from their mistakes or by teaching us new techniques,they help us harvest more game. But I suggest looking to the oldies, the fathers of the outdoor writing craft, to learn tricks that you might have not used.
I chose to shoot the 270 winchester because I grew up...