A couple more tips:
Use gold hooks, for some reason crappie love gold hooks. Also, crappie will always go up and hit a lure, most of the time while it is falling. Rarely will they go down and take one.
Personally of they are biting good I like those 1.5" tube jigs in red/white that Wallyworld sells for about $1 per 20. If you have stained water go with red/chartruse or black/green. If they are slow bitting tip them with a minnow.
Hope this helps.
Donnie