A Curriculum of Toys - an article in Make Magazine by Saul Griffith. (Thanks to +Limor Fried for the link).
Griffith examines the ways in which children can learn from toys. He lists the skills that great toys can help to develop, and looks at activities which foster those skills.
Play is a core part of learning, and good toys promote good play.
On Sunday mornings, years ago, my daughter Alex and I would steal quietly downstairs to listen to music and build things. We started when she was two, building things with sticklebricks, then moved on to duplo and LEGO.
She and I are convinced that those Sunday mornings played a part in fostering her Maker skills. If you want to see what she's made with them, take a look at Let's Get Prehistoric.
Some people dismiss play; they consider it at best a break, at worst a waste of time. Saul Griffith takes the opposite view. Play helps us, as children and as adults, to develop, to interact with others, to find out who we are and to express our natural creativity.
Playing with good toys is a great educator. Saul Griffith's article spells that out in concrete, practical terms.