NaNoMangO is basically an art alternative to NaNoWriMo (National Novel Writing Month) which takes place in November. Instead of writing a 50,000 word novel in 30 days, you draw a comic. NaNoMangO takes place in June and November.
You have 30 days (June 1-30 or Nov 1-30) to pencil 30 comic pages. They do not have to be finished, but they should be readable.
Alternatively, you can do 15 inked pages, or 10 finished pages. And you can always shoot for more!
Comics can be a new project or part of an existing project. However, only pages drawn during the 30 day period will count toward your total.
Scripting and thumbnailing (all of your planning and designing) may be done beforehand.