Think of 'drafts for username' as a private site where you can post articles - i.e. a 'holding area' - until you think they are ready to be viewed in Less Wrong.

An article can only exist in one 'area' at a time, either drafts or lesswrong.

If you delete an article, it will remain deleted regardless of which site you post it to. (I'm unsure if you can undelete an articles, but its status would remain deleted if you moved it).

Also, when you are logged in, you should be able to edit posts via their 'edit' link on the bottom right hand side of the article.

If you've ever used reddit, think of it as a private subreddit (as that's what it is).