I'm just starting to homeschool my 5 year old, but know lots of people at church who have older kids. Many of them recommend Sonlight materials.
www.sonlight.com
By that age I know a lot of people I know have their kids on autopilot practically and the kids go through their work on their own for the most part. Many also start taking college classes at a community college. It all depends on the level your child is at.
Don't get anxious about it. If you're anxious it won't work. I think the whole advantage to homeschooling is the ability to install in your child a true love for learning. Then they will continue to learn without force of help. I know many homeschool kids who really thrive on academic challenges, and can't get enough reading. Make it an adventure for the two of you to share.
If you want someone to talk to I can gladly give you an email or phone number of a homeschooler from church who has great older kids she homeschooled.
You're not nuts, but I'm curious why you made this decision with an 11th grader?