One-to-one discipleship
The Freedom In Christ Discipleship Course has been 
used by over 200,000 people in the UK to move towards maturity and fruitfulness in their Christian life. It focuses on making sure we really understand what happened the moment we came to Christ and what that means practically here and now. It also helps us shed unhelpful influences and hindrances from the past.
The course is usually used in small groups but it also works REALLY well in one-to-one discipleship.
You can simply play the DVD when you meet. Set it to pause automatically at the Pause For Thoughts (default setting) and discuss the points raised. There's no need to complete a whole session in one meeting - just pick up where you left off last time. It's good for both people to have a copy of the Participant's Guide and The Steps To Freedom In Christ.
If you prefer not to use a DVD, the mentor can teach from the Leader's Guide - all the teaching points are written out in full.
And the mentee can reinforce everything taught by reading the accompanying Discipleship Series books.