I found this page recently that Google has published, which highlights its services that may be relevant for real estate professionals.

These three suggested links under “Generate Leads” should certainly be considered seriously:

• Google Places Claim your business listings with Google Places for Business so customers can find you when looking for agents on Google search and Google Maps. Add your business location, service area, and contact details today.
• AdWords Put your money where your customers are with America’s most-used search engine for researching and buying real estate.
• YouTube Showcase your property listings in a dynamic way and engage potential buyers with the world’s largest online video community.