Okay, straight from the mouth of a former English chair. This could be spectacularly obvious from your angle, but I'm not sure what you specifically need advice on:

-Your writing sample is the most important part of your app, so go over it a lot, and have old teachers look at it.
-Your GREs (including math) affect financial aid, so keep that in mind.
-Call the admissions officer in the English department and pester them with questions ("Where do your students generally go for PhDs?" etc.) to show that you're interested in the program.