Fans of Patricia Wrede's Dragon series, (Dealing with Dragons, Calling on Dragons, Talking to Dragons)or Ella Enchanted by Gail Carson Levine will enjoy this 2002 book by Jean Ferris, Once Upon a Marigold:part comedy, part love story, part everything-but-the-kitchen-sink. Christian is happy living with his foster father Edric the Troll in a crystal cave. One day through a telescope he sees Princess Marigold reading a book of Greek myths on the balcony of her castle. Their conversation via p-mail (pigeon mail) leads to friendship and more.
You have to love Ed the Troll. He is embroiled in an ongoing feud with Mab the tooth fairy who cannot read a map. His continuing misuse of expressions such as "Kill one bird with two stones" or "Keep your shoulder to the grindstone and nose to the wheel" are very funny.