In this video, PGA Teaching Professional Travis Nagel talks about the important and many times overlooked takeaway.  The first spot where you can evaluate the takeaway is when the hands have reached waist height.  In this spot, the clubshaft should be parallel to the target line with the toe pointing straight up towards the sky.  Once in that position, simply hinge the club up and complete the backswing.

Two great drills for improving the takeaway in the golf swing:

1. Place a golf ball directly behind the ball you intend to hit.  Put your club in position to hit the first ball. When you begin the swing, simple push the second ball away with the back of the club. This will promote the proper start to the golf swing.
2. Without a club, take your normal address position and turn like you were going to shake hand with someone standing to your side.  This drill is best done in front of a mirror.

For other great tips on how to make a good takeaway in the golf swing, check out this video by PGA Teaching Professional Brett Bennett.