First of all understand it doesn't have to be all-or-nothing. Many homeschooling parents enroll in a part-time education co-op with other likeminded parents. I guarantee there's one near you right now. In these groups you essentially take turns teaching. There's almost always a parent there who is competent in an area where you lack expertise. It really just works out.

The late-game strategy that I see is enrolling in community college for advanced classes in math, physics, science, etc. In Washington state you can start this your junior year in a program called "Running Start" and it's free. At this point your homeschooling with that child is essentially over and they're taking college classes for college credit.

There are lots of home school resources and programs. Things range from sitting your kid in front of a video lecture to being the teacher yourself. Some programs are great some are just enough to satisfy the law that your kids are getting education. Frankly if you don't already know the above then you are not ready to wade through the mine field of homeschool. You need to figure out which programs are good and which are just marketing.

In the end though, while many homeschooled kids do well on tests, they all show the narrow mindedness that comes from never meeting someone who is different (religion, and political background are big ones here)

Something like Khan Academy can help with both problems. Just do the exercises, obviously they'll go wrong, explain until they go better. 1:1 feedback is much better than even great teachers.

This solves both how to teach and the bigger problem, what to teach so your kid passes the SATs.