Autodidact

For me, it was a hard won lesson to discover that my biggest obstacle to learning something on my own was the tendency to not start at the very beginning.

Yes! This is exactly what I see. Moreover, even if one does have the discipline to start at the beginning, the introductory courses are filled with material that doesn't seem relevant to the area you're actually interested in, so it's even harder to stay disciplined and learn those topics, too. But for the layperson, it's often impossible to know whether that "unrelated" material will eventually turn out to be foundational in some aspect of another field.

What I would like to see more of is materials accessible to the layperson to help them develop curricula, lesson plans, and evaluations

Frankly, Khan Academy and other similar resources are great for breaking up courses into "chunks" that are easier to digest than an entire textbook, so that's a great place to start. It still doesn't provide the feedback that you'd get from a teacher/tutor on assignments, but it would provide a decent framework if one started at the beginning and worked their way through. The only idea I can come up with to get personalized feedback at this point (short of taking a class, of course) would be to work through practice problems from a textbook or lesson plan and then find a private tutor to evaluate your work. It's pretty easy to check your answers, but if you get anything wrong it's pretty hard to find your errors on your own, so you'd really be asking the tutor to grade your work and point you in the right direction when you make mistakes.

There are people working on tools to help with this side, but I don't think any of them are all that close to fruition (AFAIK)