As an inexpensive addition to both your gun library and your computer, I would recommend the downloadable E-book called The Luger Mechanical Features, by Gerard Henrotin. This book costs less than $8.00 and has good descriptions and many fine illustrations of Lugers and their parts.
He has also produced three other Luger E-books and I recommend them all for new Luger enthusiasts. They are a great and inexpensive way to increase your Luger knowledge... the printed Reference books, such as those from Still, Kenyon, Datig or Gibson and others will set you back many $$$... and for a beginner, the E-Books are a bargain.
Follow this link:
http://users.skynet.be/HL-Editions/ebook/liste01.htm
...and drop me a private message if you buy any of them... and I will be glad to help you with installation on your computer to maximize your enjoyment of these fine books.