Not to speak for the league, but membership, from what I get from the bylaws, comes from doing stuff with the league at league events. So basically if you work or compete at an event, you are by default a member.
The links that Sam gave should be very helpful. The BOD information is a bit outdated though, Linda Hayes is the current president. There is also the NWSKL forum, but there is very little activity there: http://www.nwskl.org/forum/