A few great chest exercises:
Bench Press: Targets the pectoralis major. Whether you use a barbell, dumbbells, rocks or cans, this is a great basic exercise.
Push-Ups: Targets the chest shoulders and triceps. This is a versatile bodyweight exercise that can be done anywhere, and it can be done on the floor, or for an easier variation, on your knees or against a table.
Chest Fly: Targets the chest with a nice stretch at the bottom of the movement. You can use dumbbells or a machine.