In case you haven't heard, pictures have much higher engagement rates than any other kind of post on Facebook. Just check out the chart on the right, if you don't believe me.
What does this mean? It means that even if you post a link on Facebook and it includes a thumbnail image from your post, you're still better off posting the image itself, with a link to the article in the caption.
But not every nonprofit has access to a huge cache of great photos they can use for every blog post or link they want to share. And some nonprofits deal with subject matter that just doesn't lend itself well to photos. So what do you do?
It's easy, if you have PowerPoint or Keynote on your computer.
1. Using PowerPoint or Keynote, make a slide with text and images that express what your post is about. Something like this:
(For those wondering: Yes, that's the font from "Buffy the Vampire Slayer." Now go watch Season 2, episode 6, which is one of my favorite Halloween episodes of any television show.)
2. Go to File->Export, and export the slideshow as "images" or as a jpg, depending on what your software has available.
3. Post the picture on your Facebook page, including your status and (if applicable) a link to your blog post or article in the caption.
That's it! Easy as (pumpkin) pie.
Updated 12/3/13: Facebook has changed the way they display link posts, so this may actually not be the best advice anymore.