Some clients ask that you include images in your articles, white papers, and blog posts, and some don't. When you're asked to include images frequently, it helps to have a few go-to sources. I use freedigitalphotos.net most, but I have also used morguefile.com. You can use these images without paying royalties as long as you provide the photography credit in your work and link to the photograph or photographer's page.
Last year I started creating an image library consisting of the images themselves, along with a spreadsheet listing the links for the images, the filename, and who the credit goes to. Photos are listed in categories like "Couples," "Men," "Women," and "Computer Equipment." It took a long time to build up a sizable library, but it has ultimately saved me a lot of time. Now when I need a copy of a happy executive using a phone, I can search for it in my image library and often avoid hunting one down online and downloading it.
When choosing images for your work, you make a statement about your values, whether you like it or not. It's important to keep in mind that not all executives are white, middle-aged men, and not all nurses female, for example. Part of creating engaging content is reaching out to people. When you depict, say, a mixed-race couple or a gay couple, you're saying that you know what the world looks like, and that there's really no such thing as the "typical" person.
Some clients give you more scope for selecting images than others. For example, I have clients who are fine with the inclusion of humorous photos or captions, and other clients who want to keep things serious. Regardless, I try to make an effort to reflect a range of subjects in the photos I include with articles, because people are diverse. We come in all sizes, ages, and colors, and reflecting this in the photos accompanying articles meant for mass consumption helps ensure that no one feels subtly excluded from our content audience.
P.S., I recently released a mini-short story collection for Kindle and Nook, if you're interested.
Photo Credit: stockimages / freedigitalphotos.net