Drilling metal is obviously not as easy as drilling wood or any other kind of softer material. Metal is the type of material that requires respect and it must be treated as it should, in order to avoid injuries and, of course, get the desired results. A few things are paramount for drilling metal, as you will see right away.
A variable speed drill press is the recommended tool for obtaining straight holes in metal. While there are quite a few models available right now, you should go for one with slower RPM rates because metal needs a bit of time to cool off, and higher RPMs can make it hot pretty fast. If time is not an issue for you, pick a drill press and set it on a slower RPM in order to get the desired results, with zero headaches.
Metal, as mentioned earlier, demands respect, and that counts a lot when it comes to safety. When you drill metal, plenty of metal chips, curls and bits will start flying around. Wear your safety glasses all the time, and make sure you have all the needed safety equipment on. This way, you will remain unscathed and still manage to drill metal like a pro( For more details on this subject, see this website)
Not all metals are created equal and some of them are harder to drill than others. For instance, stainless steel is known to be among the most difficult, and there may be situations that require you to drill through this kind of material. Make sure that you have plenty of drilling coolant at hand, and use it generously, so that the surface does not get hot. Professionals recommend pushing harder into the metal, once you start working, to maintain contact with the cooler surface while you see about your drilling task.