Unless they require a very detailed lesson plan - DON'T. Keep it general and flexible enough to spend time on what he wants/needs to spend time on and zip through the stuff he *can*.
Are you a member of any local homeschool groups? Finding local resources and like-minded kids to "hang with" (not to mention like minded MOMS!) is a must for success and sanity, I think.
Also there are a number of online communities targeting different needs or groups (for instance, gifted, LD, gifted/LD, aspergers, autistic, CAPD, religious, unschoolers, Buddhist, Chinese, dysgraphic, just to name a "few" examples. BAsically - no matter your niche - there's probably a group out there.
http://www.lessonplanspage.com/WriteLessonPlan.htmhttp://www.coreknowledge.org/CK/resrcs/lessons/7.htmhttp://www.eduhound.com/lessonplan_links.cfm