For tweens and teens.
A simplified digest of Barbara Oakley's incredible MOOC on Coursera 'Learning How To Learn'. The last time I looked this had had over 1.4 million students.
Having done this MOOC myself I later signed up to be a mentor. This is mostly meet and greet rather than teaching support. We help keep people going.
I recommend 'How to Learn' as a great introduction to the topic before tackling the material aimed at undergrads and post-grads. I simply find this a great way to refresh my knowledge.