as far as good thermal paste, Arctic silver is definitly the best by far, adn Zalman makes a pretty good one..
to put it on you only need a drop the size of a large grain of rice, use somethign flat, (like the side of the little plastic casing it comes in) and spread it evenly over the surface.
old thermal paste can be removed with rubbing alcohol (80% or there-about). I usually pour some in a small paper cup, and use a q tip. I dip the qtip in the cup, adn then whipe the old paste off....