[drewitgolf]

This is an oversimplication but give it a try: Replace your Clubhead with a tennis racket head (on the end of your Clubshaft). At Impact, the tennis racket head would drive the ball both Down and Out into the ground and to the right as Bucket explained. Note: the Sweetspot of the tennis racket is in line with the Clubshaft and the racket has no Loft. The Force is always Down and Out at Right Angles to the Radius. The Club manufactures would then have to add loft to the racket face, which would make it hit the ball further right (rotate the racket face clockwise in your hand to add loft). The manufacture now creates a Lie Angle by taking the Sweetspot of the racket Head out of line with the handle by giving it hookface. Now take you old Club, without the tennis racket on it, and hold the shaft parallel to the ground. Look at the face. Which direction would the ball go if the Plane of Motion were parallel to the ground? It is not going to the right.

Your job, if you decide to accept it, is to drive the Clubhead both Down and Out from Impact to Low Point, not toward the Target. The design of the Clubhead and Face is to divert that Down and Out Force to an on Target Force (Reference 2-D-0, first paragraph on page 24). You do your job and let the Club do its job. Don't do the Clubs job! Let it do what it is designed to do.

The amount of hook face varies from club to club. Mathew did an explanation on the intersection of Planes that goes into more detail than me.
Do a search and you should be able to find it.