For this week, get started by checking out Classical Kids. These were frequently played in the car on road trips when I was younger. Vivaldi's Ring of Mystery was my favourite! You can get Beethoven Live's Upstairs free with the Classical Kids App.
These stories are great because they are fiction involving kids, but have many facts based on the composers. The background music to the story is all by the composer in the title.
Let me know which is your favourite!