There are quite a few books that will give a general idea on the theory of how it is supposed to work. There are also many threads on technique. These are probably the least value as it takes a fair amount of experience to separate the disinformation from the good advice.

As stated above the best and fastest way to learn is dirrectly from experienced skippers. If you can get on a boat with some is best, but next is just talking to them and watching what it is they do.

M