Two excellent websites 
LAOkay.com has 10,000+ links of things to do and places of see in L.A. Recently it started an architecture section, which has been growing fast.
Many photos, detailed information, and maps – featuring adobes, Victorians, Frank Lloyd Wright, Craftmen, historic, Greene & Greene, and even octagonal buildings! Many of the photos were taken by webmaster (and friend) Don Allred, who thinks he may soon have the most photos of historic abode sites online anywhere.
Don also has a humungous genealogy site, AllredRoster.com, with 147,000+ searchable entries. Both sites are free, and both run on databases he created. Nice stuff!