What is ....

What is on Die - Te rmination? Should i enable/disable?

Also what is Spread Spectrum? Some say use it some say don't?

ODT is used in multi-processor systems. It allows the individual chips to terminate when inactive rather then terminating the whole bus. Usually you don't need to worry about it in a single-processor system.

Spread spectrum:
http://www.rojakpot.com/showFreeBOG.aspx?Lang=0&bogno=133

You should leave it enabled unless you're trying to raise your bus speed by a significant amount.