I don't do much fishing around Omaha, but there is a website called Take Me Fishing (which isn't nearly as cool as this place) that you can do a look up for fishing spots in your area. It looks like it could use some input from locals, so maybe don't take everything they report for granted. I know the couple of lakes I looked up had inadequate information. BUT it is a good start, and you will recognize more stuff around Omaha than I did!
I would suggest some places to you, but I doubt you want to drive for an hour or two to go fishing at some little pond down here in the stix! Do you ever try fishing the Missouri River? Not exactly a crappie hotspot, but you never know what you'll catch in there - especially after all that water this summer!
Good luck to ya! I know this is coming a little late for what you were looking for, but maybe you can be all prepared when spring rolls around!
Good things come to those who bait.