Humans, by nature, tend to fear the unknown. This is particularly true for parents of young students when it comes to homeschooling high school. They will often think: "How could I possibly teach high school level subjects?" They also fear that their decision to homeschool high school will jeopardize their children's future, including college plans. Sometime parents will have themselves so convinced that homeschooling high school is an impossibility that by the time they reach middle school, they don't even consider it an option.
The best way to combat the unknown is by educating yourself. I spent my children's junior high years reading every homeschooling high school book I could find and talking to parents who had done it successfully. What I discovered is that homeschooling high school is not only possible, but it can be EASIER than homeschooling the elementary years! The reason is that by the time your homeschool students get into upper levels they should learn how to teach themselves. In our homeschool, it was a matter of necessity. In many subjects, my boys didn't want to wait for me to teach them (they got bored with how long it took for me to "get it.") It was much easier and quicker for them to teach themselves. My husband and I would supplement their books with training DVDs and other helps, but in general, if they learned it in high school, it wasn't because of us!
My advice is to surround yourself with friends who support homeschooling high school or who have done it themselves. My free monthly e-newsletter should also be a great encouragement to you and help you "get rid of the fear." Please consider subscribing. If you have a friend with younger students, forward them one of my newsletters and encourage them to sign up. A few years reading about how to homeschooling high school will make it will be a lot less frightening when 9th grade is looming.