When creating a web site or print piece, strong photography is a powerful communicator. The biggest challenge is getting the right conditions for a photo: it might be sunset you need, or foggy conditions, or a Winter scene (in summer). All of these mean that the image, and therefore the resulting marketing piece cannot be completed in a reasonable time.
In each community professional photographers maintain collections of their best images, just in case a client like you comes along. These images are called "stock photography" because they are ready-to-go and in-stock. When you are looking for a more generic image, or an image for another community, it is sometimes tough to find such photographers. The Internet provides a perfect resource for "stock" images, often at a very reasonable price.
Another factor to consider is the daunting cost of original photography. The cost of a custom photo shoot includes the cost of photographers, lighting, location rights, models, props, transportation, even assistants. Then you need to get appropriate releases from everybody, depending on whether the people involved are union or not, may involved rights for different media (print, on-line, etc), and geographical zones (Canada, USA, worldwide).
This is an excellent article on using photos (stock or otherwise) found on the Internet: Taking Stock: Web Photos for Free (by Tom Arah in Designer-info.com)
Here are some stock photography resources that we've found helpful from time to time: