Choosing the right drill depends on the type of jobs you will perform. For general work, a 12-18V drill is sufficient.
Check the torque of the drill. Higher torque means more power for heavy jobs. Many models offer adjustable torque.
The battery is important. Drills with Li-ion batteries offer better performance and longer lifespan than older technologies.
Consider the accessories included. A set of drill bits of various sizes and types will be useful for different tasks.