Follow the directions in the listing. Believe me when I say that if you don't *you are not going to get an interview.* Calling and asking what to do when the ad requests an emailed resume is not helping you.
If there is a name on the ad, DO NOT send your cover letter "To Whom It May Concern."
Also, turn off the change tracking on your document *before* you send it to me.
I'm surprised I have to explain these things to you.