Their are many great mapping programs, free to anyone, on the internet.  Please drop us a line if you know of any others.

REDI is a cooperative project of the San Diego Association of Governments (SANDAG) and the San Diego Geographic Information Source (SanGIS).

 http://cart.sandag.cog.ca.us/redi/

Note: REDI has  the following map layers:

• Employment Lands (data for 2000)
• Existing Land Use (2000)
• Planned Land Use (2000)
• Public Land Ownership (2000)
• Average Daily Traffic Volume (1999)
• Transit Routes (2000)
• Re-use Zones (2000)
• Parcels (2001)
• Cities (2000)
• Roads (2000)

"SanGIS is a joint powers agency of the City and County of San Diego,
responsible for maintenance of and access to regional geographic databases"

This site allows point and click parcel identification. 

http://www.sangis.org/isa/npsangis/