You're ahead of me...I've thought about multi hook rigs but haven't tried it yet. Lately I've wondered if a salt water sabiki rig would work on crappie.
As for the knots...here's a good link with several knots described. I look for the easy ones because I can remember them. There are several more difficult ones if you want to try them.
http://www.netknots.com/html/fishing_knots.html