You should have received a 'bridge' with at least one of the cards I imagine. It connects the 2 cards INTERNALLY, (inside the case, just a couple inches big/long). All you should have to do is plug the monitor in the 'master' card, and enable 'crossfire' in the driver/Catalyst Control Center
I believe they did away with the master/slave setup for ATI cards, basically insert the cards, connect the cf bridge, install your driver and make sure ATI crossfire is checked in the CCC panel, then go play some games!
I have been thinking this also. So Crossfire needs two (2) internal Crossfire bridge connector to work properly, not just one? Because I watched the official video on the ati page and it showed only one bridge connector/2 cards.