There are a variety of exercise for the chest area. The basic ones are chest presses and chest flyes. They can be completed with barbells, dumbbells, kettlebells, or cables.
Incorporating exercises for both 'strength' and 'definition' are a must. Strength exercises include using heavy weights in a rep range of 3-6 reps and doing approximately 3-6 sets of each exercise. Defining muscle requires a rep range of 8-12 reps and doing approximately 3-4 sets of each exercise. When you're lifting for a particular exercise set, you want to make the weight heavy enough to where you are nearly exhausted by the last weight. When your next workout session comes, you want to progress by either lifting heavier or completing more reps for each set.
You will want to have a plan of working your chest twice per week with rest for 24-48 hours in-between each workout session. This will allow your chest muscles to repair itself and grow from the last workout session.
With that being said on the 'exercise' front, nutrition is also of great value when it comes to increasing chest size. You will want to incorporate a healthy, balanced diet with protein, carbs, and fats. Most men require approximately 40-60 grams of protein for each meal/snack, while women require approximately 20-40 grams per each. Make sure you are also have starchy carbs before and after your chests workout as this is what will maximize your results.