What do I need to set up two DVI monitors on a 2011 Mac mini?
I've been told that I can use a mini DisplayPort to DVI adapter with the Thunderbolt port then just a HDMI to DVI in the HDMI port, is that possible?


That's what I do with a 2010 mini (MDP instead of TB). 

Yes, it works perfectly.

The tricky part comes if you want three monitors. For that, you need to be sure to buy the video-boosted Mini model that has discrete graphics, or use a (slow) USB video adapter for the third screen. But for two, any modern mini is fine out of the box.