But if you just wanted to look at some houses, here's a good place to start. This Orange County's Real Estate Page contains a search engine to search its classified ads. Unfortunately the search engine only allows city-specific searches. Data are returned in the format of a classified ad listing. This is a very disorganized site.
Most homes are in Orange County.
No search engine, listings organized by city. Good description and information, with a picture for each listing. The Press Enterprise is Riverside County's newspaper. This page contains the electronic version of its classified section. No search engine.