As Your Child's Classroom is a fantastic resource. It's by Mary Griffith. The first book I read about unschooling was John Holt's Teach Your Own . I just had such a feeling of peace come over me as I read it. That's what unschooling means.
Some people use unschooling as a method for a few subjects, and that's fine.
But that's generally called relaxed homeschooling. Unschooling is defined by the child-led aspect of the learning. It helps kids to learn to trust themselves. In the process of the kids learning these things, the parents learn the same lessons. Relax and enjoy the ride.