A dogleg is a golf term for a common shape of a hole (a hole in this case being the entire play area from the tee to the green, not the just the cup). It denotes an angled shape, much like a dog's hind leg, or a boomerang. Doglegs can curve either to the left or the right, and usually you are "hitting blind", meaning that you cannot see the flagstick which is your ultimate goal. However, when water is used instead of trees/forestry to curve the hole around, this is not the case. Although, it may be even scarier due to the finality of a mis-hit and the psychological effects that this finality creates. These holes are usually par 4s and almost as often par 5s.
Doglegs make for some very interesting golf, breaking up the monotony of long straight holes and small par 3s. They really bring a matter of choice into the game that is not there for any other type of hole. Namely, do you cut it or lay up? These are your two choices. Do you play it safe and hit an iron off of the tee, laying it right at the vertex of the bend? Or do you throw caution to the wind, trying to carry the dogleg over the trees, or even worse, the water? A pro/good golfer has a third option, which is to shape his shot with a draw or a fade to carry around the dogleg, while still remaining over the fairway, like an airliner hugging as much land as possible on it's way to Europe.
While doglegs can be scary and tricky, they also supply one of the more rewarding feelings in golf, and on a dogleg right for a righthanded player, finally allow for that slice to pay off! That is the feeling you get when walking/driving around the bend, fretting over where your unseen ball ended up, and seeing it sitting there, perched in the middle of the fairway 75 yards past the dogleg like an ivory king on his thrown with 140 yards left straight to the green. Of course, the even better result would be to murder the ball over the trees and end up on the green. I think it was Arnold Palmer I saw do this first, on a par four and John Daly is famous for these kind of gorilla shots, but if you fail, you pay the price with a lost/sunk/OB ball.
...........O... (A sample ASCII dogleg )
..........//... (where 't' is the Teebox )
.........//.... (and 'O' is the green )
t=======//..... (while '.' is trees/OB )
............... (and '=''//' is fairway )