This has come up in several conversations recently, so I think it is worthy of a post.
It is important that the images of people we use in presentations - and on our websites - show the diversity that exists in our communities and among those that we serve. When I can, I rely on photographs that I've taken, which means I can use them as I want. However, that is a limited set of images. Thankfully, some groups are making diverse images available using various Creative Commons licenses.
I have bookmarked several image collections in Diigo and you are welcome to explore them. As I find more, I add them to Diigo. The image on the right is from Humaans. I was able to choose from several images in their gallery, customize, and then download the resultant image for my use. Voila!
Among the links in Diigo, the Free Stock Photos with Authentic Diversity from TGW Studio contains links to several sites. From that list, I've gotten very good use out of the Women of Color in Tech (WOCinTech). I also like the Disability Inclusive Stock Photography.
It is likely that you'll find a subset of images which you really like. In addition, you might find new relevancy in a collection that you had overlooked. So do periodically challenge yourself to find new images. That is how I finally dug into Humaans.
Did you know that Zoom has a catalogue of virtual backgrounds? If you're tired of the same virtual background that you've been using, or just haven't found one that you like, check out this list. The links there go to a variety of different sites and was likely compiled in spring 2020 as we all began working virtually. I particularly like the ones from Behr Paint and AutoDesk. Be aware that some background have the organization's logo or name in them, which may not be what you want. Also check to be sure that any background you select works well for you and that you do not "melt" into the background. (For me, it can seem like my hair and ear sudden disappear depending in the image.)
Addendum (05/08/2022): Check out this LinkedIn post and comments for more resources!Truly a treasure trove of sources.