Orange County Real Estate

I’m beginning the fun/not fun process of house hunting in the Orange County, CA area, and am looking for advice on good online and offline resources available for finding properties in the area. My preferred method of operation is to review home listings online, check the neighborhood out with tools like Earth, and then and only then involve a realtor to get me access to view the home in person.
So: in particular I’m looking for sites that offer free/open access to search the CA MLS database, but would also welcome any other pointers / suggestions — especially advice on if there are other database beyond the MLS (for sale by owner?) that I should be monitoring. (And yes, if you know a good real estate agent in the area, I’m happy to hear about them).
Thanks in advance…