As designers, we need to have access to stock photos. We need them for use as contextual reference, mood board materials, rendering maps and so on so forth.
There are places that you can get stock photos for free. One of the best place is www.sxc.hu.
In SXC, the images are already placed into categories. You may also use the Search function to accurately source for the right images.
In order to download in images in their original resolution, you will need to register.