2 Monitors both using DVI

Yes, I believe, a DVI cable can be plugged into the dual-link DVI port to give ordinary DVI resolutions.

 

Your MacPro should have come with two DVI-VGA adapters allowing you to plug an older CRT into the DVI slot

 

The only time you need to worry is when you are using the 30" or something that needs the dual link. If you have regular DVI-D cables/monitors, they should just plug and play. Use the VGA-DVI adapter that you got with your mac pro and you should be great.

I have a DVI plugged into each port on my card, and I just used the DVI-D cables that came with the monitors (samsungs)

check this out:
http://www.pacificcable.com/DVI_Tutorial.htm

that might help.