First let's find out what muscles make up the chest and how those muscles function. The chest is made up of the pectoralis major and the pectoralis minor. The pectoralis major is responsible for flexion of the humerus (throwing motion). The pectoralis minor’s major function is to pull the shoulder out and down.
Now that we're familiar with the muscles that make up the chest area, and the primary function of those muscles, let's take a look at some chest exercises.
Flat Bench Press
The king of all chest exercises is the flat bench press. This exercise can be performed using barbells or dumbbells. The flat bench is great for strength gains, and overall chest development. For maximum strength and mass gains, keep the reps in the 8-12 range. 3 to 4 sets should be more than enough for this exercise.
Incline Barbell or Dumbbell Press
Next we'll discuss incline barbell or dumbbell press. To have a well-balanced chest, exercises must be performed from different angles. The incline press targets the upper pec area. Incline press is more difficult than flat bench press or decline bench press for most people. Reps should also be in the 8-12 range for this exercise. After 3 or 4 sets move on to decline bench press.
Decline Press
So far we've went over exercises that target the mid chest area, and the upper chest area. Next we'll go over decline press. The decline press targets the lower chest area, and for most is the easiest of the three exercises discussed so far. Decline press can be done using barbells or dumbbells. Again keep the reps in the 8-12 range and do 3 to 4 sets.
Push-Up
Last but definitely not least is the push-up. Push-ups are one of the best chest building exercises and can be done practically anywhere. Pushups are a good way to start or finish a chest workout. Finish up with 3 to 4 sets of 8-12 reps. If you’re unable to make it to the gym on chest day, do 10-12 sets of push-ups to failure (continuously do reps until no more reps can be done). 
Chest day can be one of the most enjoyable training days, at home or in the gym. The exercises mentioned should be part of most, if not every, chest workout. Keep the rest period between 1 to 2 minutes. Be sure to change the order of exercises often, and stay hydrated during your workouts for maximum performance. Now that you're equipped with the information needed to start building the chest you desire, go put the information to use and get started!
