The short answer would be no. If you don't know, then you don't need one. Also, the NB cooler ships with the P6T Deluxe... it's a little plastic fan.
They are useful for experienced overclockers, and also can be good for people who have minimal air flow through the case because most of their components are water-cooled.
The normal builder will have a CPU cooler installed, whether stock or not, that will stir around enough air in that area.