I was born and raised in Redding, California and the water from Shasta runs in my veins. Best place for sure-fire cats is Jones Valley. It's a warmer lake and Jones Valley is shallow and muddy. The cats dig it, though. If you're on a boat, keep cruising away from the marina until you get into the fish. Livers and stink bait both work well.
There's also a great run of trout that come down out of the longer arms of the Sacramento and Pit rivers. Trust me, if you catch and cook up a Kokanee from up the Sacramento arm, those catfish will be the last thing on your mind.
Bass fishing, when I was last there, was dismal. Smallies live up to their name as they never got the chance to grow to the sizes that were found in the mid-80's. Too bad, too, because they'll hit just about anything you throw at them.
Any questions about specifics on Shasta, you let me know. Maybe we can rip a lip or two when I come back from Texas.