There's a CA specific forum, where a bunch of us CA guys post, read, exchange info, brag on finds, etc.... It's the "Kinzli forum". But to get to the main page, you have to sign up. It's easy though: Just pick a name and a password. And it might take some time as the mod's check to make sure applicants are spammers or something.
The Shasta area, as you know, is a sparsely populated end of the state. So I don't know of any persons that far north posting amongst our ranks though. Give it a try and see though.
As for places to hit, you've got a lot of camping sites up there. Start out at ones that aren't necessarily super old. I mean, if they just dated to the 1950s (scout camps, church camps, etc...) to get the feel of it. As long as it's not super pounded, there will at least be clad in them. And if not super pounded, some silver coins

Once you got the hang of various signals, pinpointing, retrieving, etc... then move on to more difficult types hunting: old ruins, foundations, ghost-townsy type things, etc....