I have a book here that explains it. i will give you the rundown. kay it says that the goal is not to keep the bonsai small, but to create a balance or form and to keep the plant healthy and growing.
it says to make sure you have enough time. look at the plant often when pruning, imagining how the form will change if branches and twigs are removed.
1. remove all branches from the lower third of the front of the plant. this is the side that lets you look "inside". its the side where much of the shape of the trunk and branches are visible.
2. the branches should not point forward, but to the sides and back. only in the upper part of the crown are small branches and twigs permitted to grow forward.
3. cut one of 2 branches located at the same height opposite each other, removing the one that doesn't conform to the right-left sequence.
4. cut one of 2 branches that have grown directly on top of each other
5. take of the branches that grow to the other side past the trunk
6. remove branches that grow downward.
here is how to prune:
small twigs are cut off close to the trunk with a pair of pruning scissors.
heavier branches are removed with concave but-removing pliers.
very heavy branches are first sawed off and the part remaining is best with concave pliers. cover the larger cuts with tree wax to heal.
when pruning shoots:
leave shoots one only when they are to grow into a new branch if its growing in the right direction. and always make your cut in the direction that the new shoot is growing. prune the top 1-3 leaves or pairs of leaves after at least 6-8 pairs of leaves have developed and the shoot has already become slightly Woody. don't cut too close to the stem of the last leaf or pair of leaves, in order to avoid damage to the bud at the axis of the leaf. its possible though to cleanly remove a leaf bud my pinching a terminal bud.
always remove shoots that are of no use to the tree (wilted or dead, too close to another shoot or branch, or the y interfere with the view of the trunk.