UPGRADING EARLY 2008 3,1 MAC PRO

Hello -

I'm looking to upgrade my Mac Pro (Early 2008) see specs below:

Processor - 2 x 2.8 GHz Quad-Core Intel Xeon

Memory - 2 GB 800 MHz DDR2 FB-DIMM

Graphics - ATI Radeon HD 2600 XT 256 MB

is it even possible? Would it be worth it?

I use a lot of stuff on my current Mabook 15inch 1tb but want to move over to my desktop for editing videos, producing music, graphics design.

You'll have to forgive my 'noobyness' with this all, very new to the upgrade world...(sigh)

I've searched the forums but haven't come to a final decision on what to do / parts o buy so if anyone could tell me a definitive list I would be eternally grateful!!