Rob Antoun & Dan Thorp 
101 Youth Tennis Drills [PDF ebook] 

Designed specifically for young tennis players, this manual contains a wide range of progressive practice drills to help players develop. Fun, educational and challenging, all drills are illustrated and cover the essential technical skills, including:
warming up
baseline play
net play
serving/returning
doubles play As well as easy-to-follow instructions, each drill contains information on the equipment needed, the space required, how to construct a safe and effective training session and how to organise the participants, especially when there are lots of players taking part.