I emailed customer service at the dallas cowboys online pro shop about the media guide and was told the media guide wouldn't be available for the public to purchase.
Sadly the Pro Shop doesn't stock the media guide until very late in the season, and sometimes not at all. Same story for the Blue Book. But for the media guide, you CAN order one directly from the Cowboys. Send a check for $10 (to cover postage) to:
Dallas Cowboys
One Cowboys Parkway
Irving, TX 75063
Tell them you want a media guide and include your return address. I've ordered directly from the Cowboys off and on for the last decade or so when I can't find one in the Pro Shop. And forget mail order via the Pro Shop or even Dallas Star Magazine -- most of them have no idea what a media guide is.
Unfortunately, I don't think you can order a Blue Book directly from the Cowboys. If you're in the MetroPlex, they are generally available in local bookstores during pre-season and the first few weeks of the regular season. They are also sometimes available on eBay and sometimes in the Pro Shop (store fronts, not mail order).
For the life of me I don't know why Jerry, who is such a marketing expert in every other area, fails so miserably when it comes to marketing the media guide and the Blue Book. I wish the Cowboys would also sell the annual team photo and DCC squad photo but they don't.