If a plant or garden article could use photos to help illustrate the plant or topic, there are many sources out there available with free photos you can use to upload here. Below is a list of places with either free to use photos you can search for what you need, followed by a list of sites and photographers who's photos you cannot use without special permission, which they have generously granted to Plants.am, allowing us to use their pictures on this site.
Free photo sources
There are many collections of photos on the web that are free to use. Most still require attribution, so please follow their instructions on how to attribute photos to them when you upload the photo and fill in the photo description.
Flickr
Flickr is one of the largest photo sharing sites in the world. You can search it for "Creative Commons" photos by using the following address: http://www.flickr.com/search/?q=flower&l=comm&ct=0
That address will bring up photos tagged with the word flower. You can then search for other plants and gardening photos as well in that window.
Mediawiki Commons
Another excellent source, with tons of useful photos: http://commons.wikimedia.org/wiki/Main_Page
Special permission photos
This is a list of sites and photographers who have given Plants.am their special permission to use their photos. If you save and upload their photos, be certain to include a copyright notice with the name of the photographer, and a copyright notice saying the photo belongs to them and is being used here with special permission. If you are a photographer and want to make your photos available to us as well please let us know!