You need to know about the Turkey City Lexicon.

If you don't know about the Turkey City Lexicon, you should. It's absolutely the most useful site on good writing (in the guise of talking about bad writing) I've ever seen, and I've learned more from it than from just about any other source. (It's also highly useful if you want to be a better reader; that is, if you want to know why a particular piece of writing strikes you as good, bad, or ugly.)