On the homepage for the forum:
http://www.lugerforum.com/ there is a "see through" animation of the operation of the Luger pistol, courtesy of Gerard Henrotin, who is the author of many E-books on pistols, including several on the Luger.
For beginners, I strongly recommend you buy and download his book: "Luger Mechanical Features"... it only costs $7.95 and clearly illustrates the mechanical relationships of the trigger/sear/firing pin.
You can find his books at this link:
http://www.hlebooks.com/
IMHO, These are great books for new Luger owners, enthusiasts, and collectors.
BTW, Gerard is also a member here...
Merry Christmas!
My next post will attempt to diagnose your problem...