One of the best ways for anyone to truly understand God's faithfulness is to keep a prayer journal or spiritual diary, where he or she records prayer requests and the results of each. I have always liked YWAM's Personal Prayer Diary-Daily Planner, but now they have created a new version that especially appeals to young people (ages 9 to 14). Simple instructions for using it also cover the basics of salvation and spiritual growth.
The book is set up for one year, with monthly calendars (to be filled in with current dates by the user) and journaling pages. A few lines for "prayer priorities" show up every few pages. Each month two countries or people groups are featured with a brief description and prayer needs. "Facts and Prayer Points" data on these countries is included at the back. This helps teens, who can easily become self-centered, to focus at least some of their prayer requests outside themselves.
Scripture memory verses are provided, approximately one for every ten days. Some teens might also want to use one of the two Bible memory plans at the back of the book. One takes them through the New Testament and Psalms in a year, while the other takes them through the entire Bible.