Using the HDMI connection is probably the easiest route to take. Depending on the exact macpro you have, you will most likely need one of the adapters fromhttp://store.apple.com/us/browse/home/shop_mac/mac_accessories/cables
You could probably find the aftermarket equivalent as well. You will also need an HDMI cable to connect to the adapter.
Resolution would be set at, 1280x720, but it would probably do that automatically. It's a pretty easy process once you have the right cables, and set the tv to the proper input for the HDMI port you are connected to.