Here are some tips to help you find and choose stock photos.
1. Photography agencies have many selections. Stock photography is more cost effective than custom photography and will work for most ebook covers.
2. Be flexible. Don't expect to find the exact image you want. For example, if you provide information about home schooling, you may want to find an image of a women with a child. The images you'll find may not be the size, color, or position you're looking for and the child may not be the right age for your topic. Determine what message you want to convey. Then search for an image that conveys that message. If you don't find the right image, you may want to take your own pictures with a digital camera or hire a photographer.
3. Use a free comp image to try out the image. Most stock agencies offer a free comp image for position only so that you can try it and see if it's going to work for your purpose.
4. Buy the size and resolution you need. Don't pay more than you need to. So don't pay for 300 dpi resolution when you only need 72 dpi resolution for an ebook cover image.
5. If you don't find what you need, contact the web site. They may have images that are not featured on the site.
6. Know how to search. Try different keywords. If you are looking for a women in the woods, try keywords like "women woods, women trees, women forest."
7. Consider combining two or more images. Sometimes you have to put two or more images on top of each other to create the image you want. You can use a graphic program to do this.
In the example above, you may find a great image of a forest without a women. You may want to put a picture of a women on top of the forest image.
8. Check the "Terms of Use." Some sites only allow you to use their images for personal use, while others allow commercial use (which is what you will want for your ebook that you are selling). Other sites let each contributor of the images determine what kinds of usage will be allowed. If you're using the image for an extended period of time, you may have to pay every year.