Lots of free stuff here:
http://www.ordnancesurvey.co.uk/education-research/teaching-resources/
Stages of training
1. Talk about what you're going to learn
2. Talk about the topic itself, breaking it into subsections where necessary
3. End each section with a practical exercise using a real-workd example they will already partly understand
5. Review learning
As time progresses, you can steadily increase the amount of nav people undertake directly...
Then bring it all together with a meme, I use the 5 Ds because it works at all skill levels, if you know all of them, at any given time, you will not be lost.
- Distance (how far)
- Direction (which way did you go)
- Duration (how long have you walked since your last known point)
- Detail (what is around you, i.e. contours, woodland, etc)
- Don't go past (what is the natural boundary of your journey stage, i.e. if I walk to Brighton, I have gone too far if I end up in the sea)
The emergency 6th 'D' is Doughnut - it'll give your navigator something nice to think about while they're trying to remember whichever D they've forgotten
Drill into your students that they are not allowed to say 'Are we here', instead tell them to start the sentence 'We are HERE' - it forces them to think!
The NNAS Bronze syllabus is really good.