As of 2015, a good place to find pictures of lawns and gardens is the Landscaping Network website. The site includes thousands of pictures, and new pictures are added weekly.
The Landscaping Network provides style guides and design ideas, and photos are categorized by area.
Another good location for pictures of lawns, and gardens is the Garden Photo site. Searches can be refined and selected from a database of thousands. Images from this site must be purchased.
The DIY Network site is an excellent resource for landscaping photos and ideas. Photos of back and front yards and outdoor areas are available on the site.