Food is the key obviously. You know this already though. The question is how to get more food in to the lake.

One way is to simply go get food and put it in the lake. Trap crawdads, minnows, etc somewhere out by the Delta (for example) bring them to the pond and toss them in. That's a lot of work though, and you'd have to know where to get the crawdads (I have no clue).

The other way is to build the ecosystem to generate a more sustained food supply. To get more prey fish, you need habitat for the prey fish. So christmas trees, or even better some kind of hard woods - like if you could get some chopped down trees from a farmer's orchard. Fresh trees and brush form the bottom end of the food chain because algae grows on the fresh trees and the algae in turn feeds the prey fish in their smallest stages. Not to mention that the small fish use the trees for cover to hide from bass.

Milk crates tied together in to lego looking setups could also be good. This is the kind of stuff you see used in habitat projects around the state. Cinder blocks are a fairly cheap way to sink the trees and brush.

Once you have the cover in place, then you add forage fish like bluegill, redear, or green sunfish. I don't know which are best around here. If you put them in right now some might even spawn this year. You could also try and get golden shiners.

If the pond is your pond and you are way in to it you could get an automatic feeder for the sunfish/shiners. They sell them at Basspro.com. They shoot out pellets on a regular interval.

The only other thing I'd consider is killing off some of the bass if it still seems like they are skinny and messed up. Bass reproduce like rabbits, I mean really bass are prolific fish. So in a small pond you might just have to thin them out.

There's a few fish biology guys who read the site who can probably offer better advice than this as well. And I do believe there are more than a few books on this topic. Might be able to get some good books at the local library to save $.