The link below is probably one of the best I have run across on the subject. Written by Mark White and found on silencer research dot com. It answered about 99% of my questions, and is easy to read. Lots of practical advice, how's and whys, dissassembling tv/Hollywood bs reguarding surpressors. Most info is reguarding high powered rifles and application/effect of the surpressor on long range type shooting. I highly recommend it.
http://www.silencerresearch.com/sound_suppressors_on_high_powered_rifles.htm
http://www.silencerresearch.com/sound_suppressors_on_high_powered_rifles.htm