There are several YouTube videos by this same guy that are a really good tool for understanding mechanics. I really like the hitting videos, I think they are very relevant and well presented. I know they are baseball, but proper mechanics are the same for both sports 99% of the time. In the first video, you can see that you don't really catch with two hands, but you make a transfer quickly to the throwing hand. somewhere around 4:30 or so.
http://www.youtube.com/watch?v=eKxRzRbSnk4
Also, you do not want to use two hands to catch a grounder, you will have a girl snap a finger for sure. Proper glove techniques should be taught to prevent this from happening. The throwing hand is used above the glove to help protect the face in the event of a bad hop. The glove should make a soft move to the ball, then the GLOVE comes to the throwing hand, not the other way around... check out this video.
http://www.youtube.com/watch?v=7ZwW9kr4CGU&feature=related
I like to watch what pros and college players do and try and mimic those actions. I have never seen a pro-level player "alligator chomp" a ground ball with two hands the way people have taught kids to do for years.