John Williams is an excellent modern composer to study. His film scores should be familiar to both parents and children. I would highly recommend using Youtube to find videos of the Boston Pops or other Hollywood orchestras performing his works. This is a great time to introduce the instruments in the orchestra (including the more "modern" instruments), as Mr. Williams uses all of them in such a powerful way. I was unable to find any living books written for children about Mr. Williams. Therefore, I cobbled together the various online biographies, and we watched a few clips of Mr. Williams speaking about his life, including the interview done by Music Express Magazine, in which he speaks about his childhood exposure to music. Each week (for 6 weeks), we completed a full composer study using the workshop instructions above. After completing the composer study, (in which we just listened to a recording of the music), we watched a full orchestra perform the piece, usually with John Williams conducting.
Other options are Jaws, Home Alone, Saving Private Ryan, Lincoln, Superman and more.