When you post some offensive/bad stuff on your blog, it removes your blog to the front page. There should be a button if this happens to get it "checked by a moderator" if you clear out all of the offensive stuff.

Not that my blog was removed from the frontpage or anything...
They're currently working on improving a lot of that stuff. I think they're going for a 'self-moderation' system, so that provided you tick the 'don't show on main page' checkbox you wont be blocked from the main page or get in any trouble for making non-PG blog entries.