Usually if you're bombing one in from anywhere beyond mid-wicket, you want to throw it to the opposite side of the bowler. Like....towards the "catcher" (wicket-keeper). The reason for that is that the batsman that was hitting won't be running as fast out of the box as his batting partner, and also the wicket-keeper has on the equivalent of a catchers mitt whereas everyone else is bare handed. Little easier for him to catch a ball.

The sides switch every 6 balls (1 over), but for the most part you're just throwing it to the guy with the gloves on.