i've noticed today when i turned on the a/c the clutch engaged but i heard "click""click"click" then it worked fine,.,. so i turned off and on it did not do it again,.,.,. after a few hours i started the car and truned the AC on and it "clicked" again,.,.
what gives?

 

You could just be slightly low on r-134a. Get a gauge at Wal-Mart and check you level.