I wanted to recommend this book for it's simplicity and accessability to youth workers short of time for a weighty read - definately not weighhty, but it covers excellent ground.
It starts with the character and person of the youth worker. Your ministry will go as far as your prayer life. we expect God to bless us, without giving him his rightful place at the head of our ministries. He moves on to the issue of purity - living a clean life before God without falling into wrong patterns of living.
This book is also really practical in terms of creating a praying culture amongst young people, and the lastter part of the book focussed on mobilising young people to pray.
I know I've been challenged by this book and have just begun reading it through a second time. Enjoy it when you buy it.