http://www.paulwasserman.net/SHIII/
The tutorial is for Silent Hunter III - but the principle is the same for modern submarine warfare, its just a computer does more of the work.
However, even here the tutorial lists shortcomings in the game to take shortcuts. (eg, the 3m 15secs to calculate speed). You will need to teach yourself to convert KM into NM in order to bypass that one.
DAB
PS. I haven't listed what the forumlas for calculating, just in case you want to do them yourself. But I can, if you want?