This is an extremely noob question, but i've been trying to find a circuit that when I push a button it turns a servo 90 degrees.Well you don't really need a circuit if you are planning to use an Arduino. You wire the button to a arduino digital input pin and the servo to a arduino digital output pin. The rest is just your programming to make it do what you wish. Oh and by the way this is the servo I have http://www.sparkfun.com/products/9347.That is a problem. You bought a modified 'continous rotation' servo. It really is no longer a servo, it's rather an ex-servo. It can be commanded to rotate at a variable speed in either direction or to stop, but it can no longer be commanded to move a specific amount and stop on it's own. Get a unmodified servo if you want to be able to command it to move to a specific position and stop there.