http://opsecblog.i2p/opsec/contribute/index.html
If you think one of the existing tutorials is missing something, feel free to criticize them in their assigned issues (ping any maintainer when you do so, so we don't miss it): After discussing with the maintainer what task you want to do, we'll confirm on the price for that tutorial and after we get your confirmation we'll assign it to you, and that's when you can start to work on it.