The backdrop for most of my books are the Yellowstone and Grand Teton areas. I like to post a daily picture of the area on my fan page, which gets decent engagement with readers. I also post updates on current WIP, and a weekly teaser (linked to my blog, but I'm considering putting the teaser directly on the page). I did do a few opinion polls, which always gets readers to respond - which is great. Last summer, I was doing final edits of one of my books on location, and I posted from there, with photos of the areas that I talk about in the book.