I need a little help with catching these little beauties.

I was out today and found some nice (?) crappies in amongst some sunfish, rock bass, and small largemouth bass. I say "nice", because I don't really know what a good crappie looks like. I landed one that was about 10" and it was hard to wrap my hand around it. One that I missed was I was an inch or two larger, and the other was probably about 9".

Basically I need to know how to fish for these critters and what flies to use. They didn't seem very active, they didn't really chase stripped streamers, and they closely scrutinized each offering and usually turned away (or quickly "tasted" the fly and released it).

Any suggetions of fly choice and how to fish them would be great. They body of water is a fairly still backwater of a river that serves as a channel to a boat launch and marina. I'd guess the water temp. to be in the high 40, or low 50s.

Cheers,
Andrew