The shoulder muscles, also known as the Deltoids or Delts for short, can really make a person look fit.
Here is a basic workout to tone your shoulder muscles and the muscles just above your shoulders called the Trapezius or traps for short.

You will need some weights. Start out with 5lb dumbbells and work your way up if needed.

Instructions:

1. Stand up straight, with your knees slightly bent.
2. Place your feet shoulder distance apart and pointing forward.
3. Hold weights at shoulder height with your palms facing forward. This is the starting position.
4. Exhale and slowly lift both arms upward past your ears, above head, to a full arm extension.
5. Inhale (breathe in) as you slowly lower both arms back down to starting position.
6. Repeat exercise for a set of 12-15.

I recommend doing between 3-5 sets of this exercise for maximum effectiveness.

Another great exercise is Front Arm Raises.
These workout your Deltoids and your Latissimus Dorsi, or lats for short. These are the muscles on your back on the farthest left and right sides.

You will need weights for this exercise. Start out with 5lb weights or more.
Equipment Needed: Weights

1. Stand up straight, with your knees slightly bent.
2. Place your feet shoulder distance apart and pointing forward.
3. Hold the weights in each hand with your arms at your sides and slightly bend your elbows.
4. Grip the weights so palms face behind you. This is your starting position.
5. Slowly lift your right arm in front of your body into a full arm extension, until your arm reaches shoulder height. Be sure to keep elbow slightly bent.
6. Pause for two seconds, then slowly lower arm down to starting position.
7. Now repeat the movement for the left side.
8. Do this exercise for a total of 12-15 reps.