I've read manga like kenji or holyland that teach about fighting styles and others like addicted to curry that teach basic cooking and want to know if there are any other manga that will tellyou the basics of a topic or historicaly acurate manga like Cesare.
Sorry but those don't really teach, not sure about Hikaru no Go since it has been awhile but I sure didn't learn anything, Prince of tennis will surely teach people that tennis is destructive and.....no it is just to unrealistic to even teach. A manga by the same author of Holyland Suicide Island does the same way of teaching but in a different way.
I'll put my second in for Suicide Island. It's pretty neat, as far as learning 'survival techniques' in extreme situations goes. As far as actual lessons go, Bartender gives you recipes for drinks. Henjin Henkutsu Retsuden is not exactly 'lessons' but it does teach a bit about a few historical figures.
Can't think much about other manga I know. Feel like I'm missing one, but oh well. I also like these kinds of manga, so I'm looking forward to seeing what shows up.
I'm surprised that in both this list and the one Lilanar gives that Jin is not mentioned.
It teaches medicine/surgery, from the point of view of a brain surgeon sent back to the Edo period of Japan. It teaches both how the different medical forms are done and the history of the time period and how such practices could effect the people at that time. Good stuff.