@qvt1c - do a search here for "pulldown", there has been lots of great advice posted.
Also, see this Google doc that dacj501 posted, based on an outline I wrote:
docs.google.com/document/d/19PzKVXrYTREYv4MPOAERBIZVOJPRyCLLINrO_EDj-o4/edit
That document is not to be taken as gospel - it's merely a compilation of various coaches' advice. Mostly, the best way to learn about pulldowns is to digest the basic principles and then apply them yourself. After a few seasons doing them, you can get pretty good at estimating the cost and your chances on players.