When I first made plans for homeschooling, I was working about 15 hours a week, about 1/2 that on the weekends when DH is here. All fine and well.
Now that we're actually homeschooling, though, I got a couple big freelance projects and am working more like 30 hours a week. I've managed so far, though to do work one full weekend day, 3-4 afternoons a week, and lots of work after the kids are in bed. I homeschool 3 mornings a week and have the sitter all day. In the morning, she entertains DS/takes him to the playground (which I hate doing... a la that thread in TAO about Mom things you hate to do) while I homeschool DD. In the afternoon, she entertains both kids and I go to the office. This is a bit rough a schedule, though, so while we're on a homeschool break, I'm trying to sort of clear the decks workwise and push back or outsource a work project or two to get it more like 20-25 hours a week.
DH is a supportive husband and a great dad, but he's not involved in the homeschooling beyond the fact that everything DD does involves learning in some way.