Just put your requests on your reservation. According to Deb's site (I believe), they have just as much influence as faxes. And you can call back and change them or add / delete requests as often as you like until they are sent to the resort.
Deb's site will give you fax numbers and suggestions for how to word your request. We faxed our requests down 3 days before. Had the really important stuff like bunkbeds and no smoking on the reservation. In the fax I requested room locations, etc. We got all but 1 of our requests met and I wasn't very sure they would be able to fill that request anyhow. But if you word it nicely, they seem to be very receptive. Good luck!