If your library is a member of Flickr, consider taking pictures of all your displays and posting them. It’s an easy way to get a record of what you’ve done, and these are nice content to share with other libraries. Be sure to use the title, description and comments to give some information about the display, and if there’s a related booklist, blog posting or webpage, you can add a link to the description. It’s often difficult to read the signs and text, so it’s especially helpful if you transcribe them in the description.
There’s a small but growing group on Flickr called Book Displays in Libraries or Anywhere. The pictures there so far are all or nearly all from public and academic libraries. The displays pictured aren’t particularly unusual or spectacular, but it’s fun to browse around and see what people are doing, and you can get some good ideas this way.
It’s not always easy to see the details or displays in the standard view of photos, so look for the All Sizes link above images. If there’s a larger file available, you can often see the small details, and the read the signs and book covers this way.