Take a look at some recently published earthcaches. Doesn't matter where they are located, they should give a good idea of what is currently acceptable for earthcache "lessons" that need to be a part of the submission.
You can do that by using the Hide & Seek page, and searching for your state, and then just Earthcaches.
For example, here's a list of Earthcaches in Ontario, Canada, listed by most recent first:
http://www.geocaching.com/seek/nearest.aspx?state_id=69&ex=0&cFilter=c66f5cf3-9523-4549-b8dd-759cd2f18db8&children=n&sortdir=desc&sort=placed
Thanks, geoaware, for chiming in with your excellent advice.
B.
Wow you have tons of earth caches in Ontario! Thank you for the link. It looks like I have to figure out what a lesson is and then find diagrams to insert.