If he or she lived in a different era, then you could talk about what life was like in that era. You could also show pictures of the author at different stages of his or her life. A young child might be especially interested in seeing what the author looked like when they were a child themselves. There are many wonderful ways to celebrate famous authors in a bulletin board. You can dedicate the entire board to one author and then switch them out occasionally. This might work well for a bulletin board in a reading class or a school library. Alternatively, you could celebrate several famous authors at once.