The SCC is a large body that writes the state party platform (which has some influence on decisions by our members in the state legislature), can make endorsements on primaries and propositions, and can to some degree influence decisions about how state party money gets spent. The E-Board is a select group from within the SCC (the E-Board is around 5% of the members? I forget the exact number), which meets quarterly (rather than just the annual convention) and has somewhat more control over the same issues (including the right to make some decisions at the quarterly meetings if they can't be put off til the full convention), and does a lot of the organizing work to keep the broader SCC membership apprised of what's going on, solicit input on issues that should be put on the agenda for party meetings, etc. The general SCC membership also elects the actual party officers (chair and two vice-chairs, treasurer, etc); it looks like we actually have a competitive race for chair this year (I'm still learning about the candidates -- I have til the spring).
If you would be willing to spend a few hours meeting your local activists, and helping to shape the direction of the state party, the times and locations of the Assembly District Caucuses have started to show up on the state party website, and more should be filled in as soon as the local organizers nail down venues.
And if you are a Democrat living in Assembly District 21, I'd greatly appreciate it if you could commit to come to our caucus to vote for me. It's on Saturday January 10, at 9am, at the Hillview Community Center (97 Hillview Ave, Los Altos, CA 94022). (Note that it was previously posted as starting at 10am; as I understand the situation, the time had to be moved up to ensure enough time before an afternoon booking at the venue. Yay for the shoestring budget of local politics. Somebody recently, in an online discussion, upon finding out I'm involved in my local party, accused me of being some kind of corrupt politico, in the pocket of special interests. Ha! That's me, rakin' in the big bucks! Riiiiiiight.)
If you know anybody who is (or even might be!) a Dem in AD21, and interested in politics, please refer them to this post. :-)