What you can do is go to www.buymodelphotos.com
and check it out. Here is a brief summary. You go to the site and register as a photoseller. There are different membership levels. Each diff level gives you "X" anount of server space for images. When you upload each image, you can choose 3 categories. It asks for info about the image, IE models age, hair/eye color etc. You also put up your own price. You say how much your images are worth, no one else. Most of the images people put up are like 600x900@72dpi. If a photobuyer wants a full ress or larger size email, we are notified by email. You are contacted and given the info to discuss price with the buyer.
Hope this summery helps.