Actually, I think you may be thinking of Command and General Staff College perhaps. I did study lesson plans there. And guys left there and within a couple of years were teaching at ROTC units across the country. I do not think CGSC would claim that as their top mission, but nevertheless I think that is one thing they do. The Army War College is different though. One comes here AFTER having completed his or her 05 command, including ROTC Professors.
For example some of what we concentrated on this year included National Strategic Policy-Making (i.e how Condi Rice earns her pay); the instruments of National Power (we call them the DIME...Diplomatic, Informational, Military, and Economic elements of National Strategy), and how they can be used together to achieve our National Strategic objectives; Interagency operations (DoD, State, CIA, FBI, etc.); Joint and Coalition Warfare; strategic and operational war plans and execution; and of course some military history and military theory. Not a full list, but we do not study any lesson plans or prepare for teaching classes aimed at anyone lower than 05 or 06. Some of us will leave to command Brigades, while most of the rest will go to a higher level staff job, either in the Pentagon on the Army or Joint Staff, or to one of the Component Commands (such as CENTCOM).