Every tool manufacturer offers a line of power drills, and the one you choose may come down to something as simple as loyalty to a particular brand. Battery styles differ from maker to maker, and if you already own a rechargeable battery used for another tool, you'll want a drill that works with the same battery style. If you're starting your tool collection from scratch, the choice may come down to the drill that fits best in your hand and is most comfortable to use. In terms of performance, they're all about the same, although consumer reviews do note small differences from model to model.

The batteries used in cordless drills and other tools have evolved over the years, and today the choices usually boil down to Ni-Cad or Lithium-Ion. Ni-Cad batteries (nickel-cadmium) were once state-of-the-art, but they are gradually being replaced by lithium-ion tools, which are lighter in weight and tend to last longer. Most importantly, lithium-ion batteries are more environmentally friendly, since they contain none of the toxic heavy metals found in Ni-Cad batteries. Whenever possible, opt for cordless tools that are powered by lithium-ion batteries.

Make sure you know what you are buying when you purchase a cordless drill. The biggest cost in a cordless drill is the battery itself, so if you find a good-priced kit that comes with an extra battery, it is well worth the money. Be wary of extremely low-cost units, as it's possible they are being sold without a charger or perhaps even without a battery at all.

A good choice for a general homeowner workshop is a good-quality 18-volt cordless drill with charger and at least one extra battery. But don't be surprised if you soon feel the need for a second drill, since this is one of the most versatile tools in your DIY arsenal.