How many plans will there be, and what does a plan look like?
I'm asking because if you created one section on
a page for each teacher, they could be able to log-in
and change the text on their section only, over-writing
it each time they change the lesson plan.
I'm not sure what lesson plans are and what they look like.
You would need to determine if your webhosting allows
PHP scripting. It's possible could be done easily without