Thanks to eEuroparts for allowing me to use their picture, which shows their tensioner pulley kit that includes the left-hand-threaded bolt that so many unaware people wring in two.

It's also a nice diagram of the belt routing.

      

Description: As viewed from the U.S. passenger-side wheel well opening and working clockwise from the upper left, the serpentine belt loops around the alternator pulley at the upper left, the air conditioner compressor pulley at the top right, the water pump pulley at the front, the crank pulley at the lower center, then diagonally upward to the right and around the tensioner pulley, back down diagonally to the left around the power steering pulley, back to the right around the fixed idler pulley (the back, or smooth, side of the belt contacts this pulley) and finally back to the left to complete the circuit at the alternator pulley.  And THAT is why they call it a serpentine belt!