I don't think now is a good time to sell anything in L.A. Especially raw land. Just my two cents.
As was said above, Loopnet is a great place for listing a commercial property. There are many places to start and I'd suggest you talk to an agent with the clientele and know-how to find a buyer for a property such as yours. I would love to talk to you more about your land as I have several big time property owner clients of mine in Los Angeles who are always looking for land & commercial property. Maybe one of them would be interested?
Call me anytime - 323.333.6222