Resume transmittal
Depending on your time-frame, either mail or overnight delivery would be fine. I would place a resume and cover letter in a 9 x 12 envelope. That way you do not fold them and they arrive fresh, neat and crisp. Fresh, neat and crisp wins you points.
I realize that application transmittals have changed in the nine years since I was looking, and that e-mail and faxing is commonplace. Call me old-fashioned, but I would do neither. Look at it this way. You lose a lot of crispness and clarity via fax. Compare a faxed document to its original. That loss of crispness and clarity can screw you if the document scans incorrectly. When you e-mail something, you run the risk that your recipient's word processor will not read your document's format. Moreover, H.R. receives tons of faxes, so you risk having your e-mail, and your hopes and dreams, deleted or ignored. It's much harder to ignore an original document that arrives in an envelope.
Original documents are the way to go in my $0.02 opinion. Good luck with your application efforts.