Susana over at 4Real has just shared some fantastic links, online Eucharistic books for children.
They have come from The Real Presence Eucharistic Education and Adoration Association.
The first link is Eucharistic Miracles and Saints
The second, The Eucharist, The Bread of Eternal Life.
These are simply wonderful, perfect for First Holy Communion preparation. I encourage you to pass these links far and wide!
Editing to add (17th July 2012): I have just discovered that the Real Presence site has since added a new display, Apparitions of Angels and Demons.