General energy flow and control is a very important part to magick, it helps you focus and cast spells. Energy manipulation is a technique to grasp and control amounts of energy to send to the universe for your goals. Energy is the basis of all magick, without it, you won't go far. Here's a couple exercises to get you started.
Sit in a comfortable position and get relaxed. Have your palms 1 or 2 feet apart, facing each other, resting on your knees. Visualize a ball of energy in your chest. Then send this energy (using visualization) through your arms and palms, creating an energy ball between your palms. Really see it, make it clear to your minds eye. Now slowly move your palms together. You should feel a sort of pressure, cause it really is there! Don't stress if you don't get it right away, practice makes perfect. When you are finished, I suggest you ground the energy. To do so, just visualize that energy going back to mother earth and letting her take care of it. This is used energy and is unwise, in my opinion to keep it after it's been used.
When you feel like you've got this down, here's an advance version.
Do the same as you would in exercise 1, but when you have the ball of energy (also called a psi ball by some), manipulate it into different shapes. Try a ovular shape, a pyramid, a square. When you think you've got that down, try something more detailed. Try shaping it into a fruit, like an apple, or maybe a leaf, with the veins and everything.
(I take no credit for these exercisses, all came from a talented friend of mine)