I find the more we follow our kids' lead on what they're interested in learning, the more they'll come to us and ask for input. The more we foster their love of learning, the more they soak up learning like sponges. They come to us constantly and ask stuff like, "I learned on PBSKids that the pyramids were built using an inclined plane. What else uses an inclined plane, Mommy?" In fact the other day I had to tell my son, "Please STOP doing addition and get your coat on so we can go and not be late!" I then realized what I'd just said and burst out laughing! What a wonderful problem to have!
But yes, we have input in our children's learning, generally at their request. Our whole family delights in learning and the more we adults keep learning about what we're interested in, the more the kids do the same without any sort of pushing or coaxing. Hubby was all excited today over a thick theological tome by NT Wright that he got form Amazon and I have been going around in seventh heaven because I got my braille transcribing certificate from the Library of Congress. Hubby took a Jazz Theory class at the university just for fun. I've been writing fanfiction and studying calculus. The kids see this sort of activity and they don't think it's odd at all to want to learn how multiplication works. Since they know we know how it does, they come ask us.
We definitely don't see the children as the only unschoolers in our family. We're all at just a different level of learning. The 14-month-old is learning to climb stairs. The four-year-old is learning the names of the planets in the solar system. The six-year-old is practicing reading and preparing for her Book 1 recital on violin. Mommy is building a harp in her wood shop. Daddy is programming a web-based program to analyze Jazz chords. We're all learning things that interest us and we all ask one another for assistance all the time. I ask my daughter for help with the laundry because bending to get the clothes out of the dryer hurts my back. She asks me to teach her to multiply because she knows I know how to do it and she wants to know how.
I suppose this sounds somewhat idyllic... I don't mean to paint it with a rose-colored brush. I mean we really do all those things. But there are days when we sit and watch "How to Train Your Dragon" all day, lol. But we trust our kids' curiosity and we figure we'll eventually get around to everything they need to learn without all the angst of forcing them to follow an unnecessary, arbitrary schedule. Our parental input consists mostly in trying to keep up with the million of questions our little learning machines put forth!