As a relatively new resident of Marin myself (moved 2 years ago to Mill Valley) I agree with the suggestions proposed thus far, and will add that we followed our instincts and similar advice then, and have been renting and "scoping" neighborhoods ever since.
We found a perfect rental a couple days before Christmas in 2006 and have been there since, waiting, watching (every single new listing in 94941), worrying (about the job market) and doing just fine all in all.
I would absolutely not be in a rush to buy anything in Marin. Prices have come down, and inventory has risen, but too many factors are still unsettling - not the least of which are those pertaining to the California fiscal nightmare, Bay Area employment, school funding (varies district by district), etc.
That said, we left a part of Southern Californica we thought was paradise, only to find that Marin is in a different league all it's own. We couldn't be happier. Find a good rental (lots of homes to choose from now that many sellers have yanked their listings and opted to manage their properties instead), move in, have fun and find out what area you like best. There is plenty of special communities to choose from.