I just Installed my CPU. I have a Thermal compound.
But should i put it on now then install my CPU cooler? or not to use it all do to the fact i have air cooling?
Yes, you always apply the thermal compound to the top of the CPU before mounting the CPU cooler (unless it is the stock cooler and has the thermal compound on the heatsink already)
Put a small "pea sized" drop in the center. Some people may say to use a small line, but it spreads more evenly if you use a small pea sized dot in the middle. Either way it will cool just the same.
The proper way to do this is to place a small line, X, or dot on your cpu depending on how many cores you have. Then push your heatsink on top and LIGHTLY twist the heatsink a few degree's each way and this should spread out the paste evenly.