I've mentioned the topic of photos before but it's time to cover it in more detail. If you want to write an article for me or just about any other magazine/newspaper editor, it is almost mandatory that your article be accompanied by a suitable photo. Really. We will not publish the article without a photo, even if the article is on the most interesting subject imaginable.
For a photo to properly illustrate an article, it has to be relevant to the article's subject, it has to be clear and reasonably well lit, it has to be high-resolution and it has to have caption information. If any of these items is missing, then the photo is no good and can't be used.
The first of these -- relevance to the subject -- is obvious, so let's go on to "clear and reasonably well lit." If the person or product that is the subject of the photo is out of focus or otherwise not visible because of poor light, then the photo is no good. Turn on and use your camera's flash, even if you are outdoors in the sun. Stand close to your subject to get the most effect from the camera's flash. Take multiple shots and pick the one that looks best.
As for high resolution, at least 1,000 x 1,000 pixels (one megapixel) is required for clear publication. All digital cameras and modern cell phones have cameras with MUCH higher resolution than that, so set your camera or cell phone to its highest resolution and take the photo. Force the flash on. An alternative is to shoot a short HD video clip and extract a still image from the clip. Full HD video has a resolution of 1920 x 1080 pixels, which is more than enough for clear publication.
This is a great photo, but it doesn't help the article unless there's a caption that explains who/what is in the photo.
Finally, a caption that explains what's in the photo is required. If there are one, two or three people in the photo, then each needs to be identified by name and title. If there are more than three people in the shot, then only the primary person needs to be identified with name and title. Of course, the product and activity needs to be described. (e.g., "Jenny Jones of Wildlife Shooters tries out the new Sony TurboZ camera at the polar bear exhibit at the Philadelphia Zoo.")
I've taken more than 1,000 photos that have been published in various magazines and newspapers, and it's the captions that take the most work. The photo is not usable without a caption, so collecting caption information is critical. Scrimping on caption work can anger company representatives ("How the hell didn't you know that was a Sony camera?") and embarrass people who are misidentified or whose names are misspelled.
I hope that takes some of the mystery out of getting photos to accompany an article. Let me know if you have any questions.