Are you trying to find terrestrial NPP, oceanic, or total?
You can obtain terrestrial NPP from MODIS via the LP DAAC.
Ocean NPP based on SeaWiFS data is available here
http://sites.science.oregonstate.edu/oc ... ductivity/ This can probably be used for basic estimates even though the time period is 1997-2009.
For more recent data, look under Custom Products
http://sites.science.oregonstate.edu/oc ... custom.php
This page has a few annual Land/Ocean merged NPP products.
http://orca.science.oregonstate.edu/216 ... .merge.php
I hope those will be useful to you.