B&W photography has been there for ages until it fell out of favor once color photography burst upon the scene. Nowadays it's not considered old and out anymore and has become popular again. Why do people choose the black and white? Is that the timeless and nostalgic look it gives? Or just something artsy? As there's always a chance you have never even taken black and white photograph in your entire life, I guess we should give it a thought.
What you should understand before experimenting is that black and white photography first of all is a great learning tool - it helps you understand that limit where colors fade and decide whether and how you should take the picture. What's more, it helps you grasp all the concepts involved in color photography or in digital photography, which you might later find tricky if you haven't got a thorough understanding of black and white photography already.
You may either change your camera settings or use some dedicated software afterwards to change your pictures to B&W later - both of which are great learning tools and that is why we're not going to go into that (just remember it not always looks the same). Let's focus on the subject, colors, light and background first.
First of all, remember that any subject you photograph does not rely on color for its beauty - the colors may look striking, but they will be nearly indistinguishable in the photo. This is why you should choose your subject carefully. Some subjects that look interesting in color look dull in black-and-white. On the other hand, black-and-white can create an unexpectedly intimate portrait or suddenly transform a simple scene into a dramatic moment, heightening the emotional content. This is why people usually look especially good in black and white. Make sure the background does not distract from your subject. Sometimes moving your subject just a bit to a side is all that you need to eliminate unnecessary elements. If that does not work, try different angles.
Buildings, landscapes, and other scenes are also valuable subjects in black-and-white photography - just watch the light and keep an eye out for the unexpected, as light plays a much bigger part in B&W than it does in color photography and that is because you have fewer elements to choose from. Some would even say that light and shadows are all there is in black and white photography, this is why you have to experiment with it so much - try taking pictures of the same scene at different times of the day and you'll see how important light and shadow are to the mood of a photograph.
Switch to B&W whenever you feel like it or at least so you do not forget you have such an option. Remember, anybody can produce black and white photos, but it takes a little more thought and skill to produce good black & whites, so keep practicing and you will be making some absolutely beautiful shots soon enough.