it depends on what works for you, but the number one tennis player, Novak Djokovic uses the head tennis racket, and it works really good for him.
The one(S) in your racquet...nut bar
You can generally string your tennis racquet at any of the following places:Specialized tennis storesTennis/Racquet clubsYour coach (coaches generally string your tennis racquets for you)Certain sporting goods storesTennis academies
When you hit a tennis ball with a tennis racquet, you want the ball to contact the sweet spot of strings.
The size of tennis racquet you choose is really a personal preference. Basically, tennis racquets come in a mid-size and oversize. The mid-size racquet has a smaller tennis face and less surface area of tennis strings. Mid-size racquets are more compact and usually lighter. They are easier to swing and move around quickly. Serve and volley type players often prefer the smaller mid-size racquet. An oversize racquet has a large surface area of tennis strings. This can make the racquet feel heavier and it is more difficult to swing the racquet around quickly. However, the "sweet" spot on the racquet is larger. The sweet spot is where you want the ball to hit your strings more maximum effectiveness. Players that hug the baseline tend to enjoy using an oversize racquet. You can always "demo" different racquets at your tennis club to see which size is best for you. Your tennis pro can also give you great reccomendations.
For most of the best racquets used by professionals preferred material is graphite.
A tennis ball?!
Racquet comprising a ball striking surface, a racquet head frame, and a racquet handle. Different dimensions and lighter than a tennis racquet.
keep your racquet in a tennis case. :)