usually you're advised to put it where the sun would naturally touch your face. so, careful don't load your brush with bronzer or you'll look fake, it would be the chin, your nose, i prefer putting bronzer on the hairline rather than the forehead (looks "dirty" on me as i don't naturally tan).
i also use bronzer for contour, so i apply it also on my cheeks (i do that fishy face and put it in the hollow), and with what's left on the brush i also accentuate my jaw.
i like Elke Von Freudenberg tutorial, search her tuts on youtube, i found them very helpful.