Considering you know about the search function and buy a chiltons option, I will say this because I am feeling generous this morning.

Standing in front of the engine bay, you must first losen the nut (14mm) on the back of the tensioner pully. Only need to loosen it a couple turns. Then there is a worm drive bolt (14mm I believe as well) that faces the radiator. Tighten this bolt to draw the tensioner pulley toward the motor (tighteninng the belt overall) or loosen the bolt to back the tensioner pulley out (so you can first get the new belt on). And as for proper tension of the belt, I am not going to go into that. If you have not changed belts before, I cannot describe the feel and deflection of the belt you should be looking for. Buy the chiltons, it is better described there for the home mechanic. Good luck.