Torpedo Targeting

Okay guys, I have my copies of the newest three SH on the way to me.. However, as I try to grasp with the whole manual targeting I notice something.. in all of the explanations I see on here, (even though Ive had trig) I cannot seem to understand the methods of targeting.. Is anybody willing to (preferably on this thread) explain in simple newbie terms (if you use abbreviations, please use parenthesis and spell it out or explain what the word means) and explain how targeting works as far as setting torpedoe courses.. Please and thank you all

USN SR Casey Smith