We decided to homeschool because the local cheder simply wasn’t able to provide what our child needed. I had taught at the school and knew the secular studies program was not strong. On top of that, our child was academically advanced. He was reading before he was four and working with fractions, decimals and negative numbers before he was five. By their own admission, the school did not have the resources to keep him stimualted all day.
Teaching elementary subjects doesn’t take a lot of preparation – we’ve all been through elementary school. There are many good websites with free materials for both secular subjects and limudei kodesh.
We opted to not join a homeschooling support group, but many homeschoolers do. The groups go on field trips, do group projects, etc. so kids get the experience of doing things as a group.
We have one child, but I know many people who homeschool multiple kids.
One thing anyone who is considering homeschooling needs to do is check state law. Although homeschooling is legal everywhere, laws vary by state and some states have more requirements than others.