Binoculars are one of the most useful tools in an amateur astronomer's arsenal. They provide spectacular wide field views of the Milky Way and large deep sky objects like the Pleiades star cluster, the Andromeda Galaxy, and the Double Star Cluster in Perseus. For the telescopic observer, they are the exploration tools to use to plan the path through the stars when you are starhopping to a faint object. Never leave home without them!
The most useful binoculars are those with relatively low magnification, such as 7x50 and 10x50. The first number is the magnification; the second the diameter of the objectives in millimeters. These can be hand held by most people and, under a dark sky, can provide hours of observing enjoyment.
There are also larger binoculars which are more specialized instruments. These generally need to be mounted on a tripod to be steady enough for use. Binoculars as large as 25x100 (equivalent to two 4" refractors!) are now available at very reasonable prices.