Yeah, the wonderful world of MODx permissions!
There's really no "quick-n-dirty" way to do what you are looking to do without getting into the permissions, and if you don't have at least passing familiarity with how it works, it can get screwed up fast.
My whole-hearted recommendation is to set up a local test site, and follow all of Bob's permissions guides a couple times.
But take heart, once the 'aha!' moment comes, it will all make sense why it's done this way. Well... it did for me anyway