Try Jackson lake over by Key Center. I did not catch any there but I was right next to a guy pulling them in left and right near a big brush pile. Just hook up a colored jig and put a worm, maggot, minnow, or grub on it. Here are some articles on crappies.
http://visitors.fishingclub.com/mag_articles/article_8.asp

------- http://gameandfish.about.com/library/weekly/aa036101a.htm
----------- http://www.insportsman.com/infishing/fisharticles/crappies.html

If you really want to catch them, the guide mentioned above told me you can catch 700 a day during Sept and Oct at Silver Lake. Big ones. His name is Roger Luce - but he is on sabbatical this year and is fishing instead of guiding. There are some other lakes on the other side of the bridge that are good for crappies as well. Spanaway, Ohop, Kapowsin, etc.
Good luck. I just started going after crappies myself.