Choose a Type of Cherry Tree
First, consider your climate. A USDA Plant Hardiness map divides North America into 11 climatic zones. You can learn your zone with a quick look at the map.
As a general rule, sweet cherries grow best in zones 5 through 7, where summers are typically mild and where winter temperatures are only moderately cold. Tart cherries have a wider range, growing well in zones 4 through 9. If you're not sure which cherries are best for your climate, check with your local extension service.
You will also need to decide whether you want a standard, dwarf or semidwarf tree. Standard sweet cherry trees can reach heights up to 40' tall and nearly as wide. This can be too large for many home growers, so dwarf and semidwarf trees (which can range from five to 20' tall) are more common in home orchards.
Another factor to take into consideration when buying a cherry tree is its chilling requirement. After a cherry tree goes into dormancy in the fall and loses its leaves, it requires a certain number of hours between 35 and 55 degrees Fahrenheit in order to produce well. Fortunately, this is a factor that is taken into consideration when trees are rated for various climate zones; if you select a variety rated for your zone and recommended by your local extension service, the chilling requirements will have already been factored in.