I need some tips on making a third person aiming system?

(Before I ask my question please make sure you have knowledge about my question instead of posting answers that I'm,asking) In my game it is a third and first person shooter. I need some tips on how to make a aiming system, like say you equipped the gun, and your character is facing you. Then you click rightmouseclick and your character is automatically faced in the direction of the cam with a cross hair in the center of the screen. So any tips on were I can learn about this or do you have any types?