How can I install the most recent software and firmware updates?
From the Apple () menu, choose Software Update. Install any updates related to OS X.

How can I tell if I have the most current OS X software?
From the Apple () menu, choose About This Mac. If you see "Version 10.9.1" or later, your Mac Pro is up to date.
 

How can I tell if I have the most current firmware?
From the Apple () menu, choose About This Mac and click More Info. Then, click System Report. You are up to date if you see the following in the "Boot ROM Version" field: "MP61.0116.B04".

If you do not see these version numbers, you should run Software Update and follow the instructions until there are no more available updates listed for your computer.