Hi Michael, welcome to the site and acting upon your interest in Luger pistols.
They are fascinating from so many points of view. History, industrial age technology, business operations in Europe, politics, etc...
The reference books are generally issued in limited editions, and quite expensive. I think of them as "Luger University" and recommend study. You pay Luger University tuition by purchasing books, or by making mistakes purchasing Lugers.
A good, if older, introduction is called "The Luger Story" by John Walters. It's out of print now, but you may find is used through Amazon or Abe Books online. As with anything in this field, the information ages as new things are discovered.
The Jan Still books are collector references covering the Luger eras. Costly but considered essential for the eras covered.
It's a good idea to decide on one of the eras (Early Lugers; Imperial (WW-I) Weimar, WW-II, Post WW-II and start your focus there.
"The Mauser Parabellum" is a good overview and collector reference by Hallock and Van Der Kant. It covers the Mauser manufacturing period. "The Parabellum Is Back" is a good post WW-II reference.
Bobba published a beautifully illustrated book on the Swiss Luger that is still available new. See Abe Books and the DEA Store in Rome for copies.
Lugers at Random is interesting, if dated. Ed Tinker's book on Simson Lugers is an essential reference for those pistols. There is a good collector reference for Krieghoff Parabellum pistols published by the family.
I know of no museums that focus on Lugers in the USA. There are European museums like the Oberndorf am Neckar museum that focuses on Mauser and the Swiss Arms museum at the Bern armory that have good historic collections that include Lugers. In the US, the NRA museum has at some, but it's not their focus.
An online virtual museum for Lugers would be an interesting project. Something with good photographs and historic information.
This site has interesting information...
Marc