Saddles are also adjustable back and forth. Ideally, this adjustment should be made to set the saddle at the correct distance behind the bottom bracket, so that you are pedaling at an efficient angle. The conventional wisdom is that, when the pedal cranks are horizontal, your knee cap should be directly above the pedal spindle. See Keith Bontrager's article on this topic.
It is generally considered a Bad Idea to tinker with saddle position to adjust the reach to the handlebars; it is better to adjust this by replacing the handlebar stem with one with a different reach, or by buying a bicycle with a different length top tube.
The angle and the front-back position are both adjusted by the clamp on the seatpost.
What is the pedal spindle? Do you pay attention to this or do you just mount a new saddle and go riding? I have never fooled with a saddle but I am getting ready to attach the one pictured. I know that preferance will again come into play but it looks like the way Sheldon says is the most efficient.