Unschooling Young Children
You don't need to unschool young children (children not old enough to fall under the compulsory schooling law) because they're doing it naturally. Children are born with a natural ability to learn, as these, and many other books and materials make clear.
Learning All the Time by John Holt
How Children Learn by John Holt
Young Children: Natural Learners by GWS (out of print)
Young Children Learning by Barbara Tizard and Martin Hughes (Harvard University Press, 1984; 2003). Turns upside-down the commonly held belief that professionals know better than working-class parents how to educate and bring up children. Buy now
The double-edged sword of pedagogy: Instruction limits spontaneous exploration and discovery. Research from MIT published in Cognition, 2010.