Other than understanding that the tube propells a projectile out and up to eventually land on or near the enemy and explode I don't know a ton about artillery mechanics. How do the gunners aim and how accurate were they with initial fire. Did SP arty use the same means to aim?
JBark, you are asking a lot their. Maybe you can start with this link in Wikipedia: Artillery - Wikipedia, the free encyclopedia There are a few links in the text, for example about azimut, that can explain the system of aiming. Other links: Artillery Aiming Procedure Indirect fire - Wikipedia, the free encyclopedia I hope this gets you a bit further.
Fine site to begin browsing principles and abilities of WW2 Artillery: BRITISH ARTILLERY IN WORLD WAR 2 ~A
This introduction to artillery for trainee battleship gunners is one of the best texts I've seen. Part B covers internal ballistics, and Part C covers external. It's even fun to read!