This excerpt is sure to hook you:
Many beginners assume that the job of binoculars is to enlarge an image, so it must be better to buy the most powerful binoculars they can find. This is a mistake, because brightness and field of view are far more important than magnification. In fact, too much magnification makes binoculars useless. Keep in mind that binoculars that magnify an image eight times also magnify the small movements of your hand eight times. Ten-power binoculars magnify those movements ten times. The more the image moves, the less useful information you get from it.
Read the entire guide at this link and download this very useful cut-and-keep PDF.