As I've written before, because California isn't a battleground state, we don't get many national political ads, but every election, we're absolutely deluged by ballot proposition ads. Most are fairly well made from a technical standpoint (the benefit of being in a film industry state), but some are simply propaganda, ranging from the clumsy to the slick. Here's some information for voting.
The California Secretary of State's voter guide online has the specific ballot language, fiscal impact, arguments for and against, and links to the for and against websites. Click on the individual ballot measures in the left hand column for more information. If nothing else, I find it useful to see who's for and against different measures.
On Which Way LA?, a local NPR show, host Warren Olney leads discussions on individual measures, inviting proponents for each side on. Scroll through to find a specific discussion.
The Los Angeles Times and Sacramento Bee don't have comprehensive guides up yet, but do offer some stories on individual measures.
Perhaps of most use to liberal Californians is Calitics, a site for progressive California politics. Here's a snapshot of their endorsements:
(Click the image for a slightly larger view.)
The actual entry explains their positions, and other posts in their endorsements category go further in depth.
I plan to cover some of the other propositions in greater depth myself (especially Prop. 8), but here's a start.
(Cross-posted at The Blue Herald)