Card Games by John McLeod [ Teens/Mature Teens ] - A collection of dozens of card game rules arranged alphabetically, categorically, and geographically.
USPlaying Card Company: Children's Card Games [ Kids/Teens/Mature Teens ] - Has instructions on how to teach children how to play card games, and the rules for several games for children from 4 to 12 years old. Gives the number of players, suggested age range, and skill level for each game.