I'm answering my own call with this post. I want to write a bit on why I feel comfortable homeschooling my kids despite the fact that my formal education ended with high school. This is for Steve but I think it will also make a good addition to the archives for future use.
1) Current subject matter. My two are officially in Primary and Grade 4. There should be nothing in the elementary school curriculum that poses any great problem for a high school grad.
2) If I need a teacher for my child who has mastery over a subject, I can find one. Homeschooling does not mean the parent simply steps into the role of teacher. More often we're facilitators and coordinators. My daughter has an interest in calculus? I know a college prof who adores calculus (not to mention how her eyes light up when quantum physics is mentioned). My son wants to pursue microbiology? I believe there's an uncle on my husband's side. Either one interested in tearing down an engine or the principles of flight? I have a dad and two brothers who are aircraft engineers. I had a friend whose 12 year old son had a passion for geology. She found a local professor, had her son write him a letter and voila! Her son now has a mentor on the subject.
3) Homeschooling material is different from school material. I have two types of curriculum that's used regularly in our house that does not require an instructor with subject mastery. The first is the scripted curriculum. I am in no way qualified to teach my kids grammar but I knew that and bought Winston Grammar. It's a scripted curriculum that tells me exactly what to say, anticipates questions from my daughter and generally guides us both gently through the subject. The second type of curriculum is self-directed. This is our Singapore math and the ancient Greek workbook, the Greek Hupogrammon. These texts cut me out of the picture and direct the script right at the child. When the subject matter is completely out of my territory it will likely be self-directed courses and curriculum my kids will follow. Teaching Textbooks is an excellent example, The Teaching Company is another one.
4) I can learn. So I didn't go to college. There's nothing to stop me from picking up a book on atomic theory or joining a message board full of textual critics and biblical scholars or listening to lectures on the Roman Republic. My brain stills works quite well (much better in fact then when I was in school) and I can learn enough about the Gracchi brothers to give my kids a decent account.
PS: Note that I've only given the 9 year old a decent account of the Gracchi brothers. I don't want to give the 6 year old nightmares. :)