The driver is the biggest, longest, and the most expensive club in your bag. Drivers are most often used off the on a long hole, such as a par 4 or a par 5.  The drive is your first approach at the hole and gives you the lie for your second shot, setting you to hit off the fairway or the rough.  Though the club is only used 75 percent of the holes, and for only one swing, this club usually sets the tone for that hole, and sometimes, the round.  Here are some pointers when selecting the proper driver for you.  Please remember, it is always best to see a golf specialist to get a custom reading and fitting for your swing.
 
Choosing the right club head

Size
There are 3 general club head sizes for woods, also known as fairway irons:

• Standard - Measures about 150-155 cubic centimeters and provides better control, and a potential faster swing, but a smaller sweet spot.
• Midsize - Measures about 155-250 cubic centimeters in size and is a nice sized club head with a nice sized sweet spot, though this club is a little harder to control than the standard sizes.
• Oversized - The largest club head size, 250 all the way up to 460 cubic centimeters offers largest sweet spot of all the club sizes but remember, this is more difficult to control due to he size.
  

Materials
There are now 2 basic choices in the materials woods are made of. The choice is really one of an individual golfer's preference for look and feel.

• Stainless steel- Less expensive, but slightly heavier than the more modern titanium and other alloys.  Stainless steel has a more traditional look and feel because of the slightly smaller head which is necessary because of the heavier weight.
• Titanium - Lighter weight allows for the creation of even larger club heads and has a larger sweet spot.  They can be more forgiving on mishits.
  Choosing the right shaft

Flex
Flex is the amount of bend in a shaft.  Your shaft flex needs to match with the speed of your golf swing. A shaft with more flex helps the ball fly farther, appropriate to your club swing.  There are five general levels of flex in shafts: L for Ladies, A for Senior, Regular, Stiff, Extra Stiff.
 

• Beginners and players with less powerful swings will benefit from a more flexible shaft.
• An average player with a swing speed of 75-90 mph, and should look for a regular shaft.
• Players with powerful swings - in the 90 -110 mph range - should purchase a stiff or firm shaft. This will provide a stiffer club for more control.

Materials
Golf club shafts now primarily come in 2 materials:

• Steel shafts - Stronger, more durable and less expensive of the two materials.  Offers consistency from shaft to shaft because of a more advanced manufacturing process.  Steel also offers more control on shots, but can cause a slower swing speed because of the weight of steel.  This is recommended for stronger players who want more control in their game.
• Graphite shafts - Generally lighter than steel and can be made in many more variations, making it easier to select a shaft best suited to your game.  Great for those that demand customization, but can be generally more expensive than steel and less durable.  The lighter weight of graphite allows for greater swing speed for more power, but it sacrifices control.

Choosing the right loft
Loft is the measure of the angle of the club head.  The greater the loft, the greater the angle on the face of the head and the more control but less distance, whereas when you have less loft, you get greater distance, but at the risk of less control.  Generally, a the loft on a driver is between 8-12 degrees, and the angle is dependent on you club swing.

• Slow swing - 10.5-12 degree loft
• Average swing - 9.5-10.5 degree loft
• Fast swing - 8-9.5 degree loft

I do hope that this information is helpful in choosing your driver.  This decision can be a hard one, but with a little info, you will find the best club for you.
 
-Information provided by club-golfcom