Finding the right binoculars depends on the purpose for which they are going to be used.  For example, someone who uses their pair to go bird watching is going to have different needs than someone who uses their binoculars for a sporting event.

First, decide on the power you need for your binoculars.  Two numbers, such as 7x42, represent the power.  The first number is the amount of magnification you will receive, and the second number is the size of the lens.  Both of these affect the quality of the view.  First, the magnification is how close the object will appear to you.

The magnification number is the number of times that your normal vision will be magnified.  The larger the magnification, the less bright the object will appear.  This is why lens size is important.  The larger the lens, the more light is allowed to reach your eye.  So the best option is to couple a large lens with a high magnification.

Another item that affects how bright your view will be is whether or not you choose a coated lens.  A coated lens allows more light to reach your eyes, giving what you are viewing more contrast.  This is a nice option, but it will increase the cost of the binoculars, so if you are on a tight budget, coating can be overlooked.

Finally, test the pair you are considering purchasing to make sure they focus well for your eyes.  This is important, because not all pairs of binoculars focus the same way.  Make sure you can see clearly through them before you buy!  If you are considering buying a pair online, check them out at a retail store first.