Shooting in color allows you more options for creating a black-and-white photo with editing software, such as Photoshop, Lightroom or Paintshop Pro. Some editing programs will let you convert an image to black and white in such a way that you still can adjust colors by channel. You end up with more control in post processing a black and white image if you shoot it color.
And if your camera has the option of recording images in the raw format, do that. Some cameras might allow you to shoot in black-and-white jpeg and full-color raw at the same time. This gives the advantage of being able to preview the photo in black and white, so you can make adjustments and reshoot the picture, while retaining the color information within the raw copy, for working with a photo editing program.
For this step you don't even need to leave your chair. Make copies of some photos that you have stored on your computer and convert them to black and white with a photo editing program. And the software doesn't have to be anything special. Many PCs and Macs will have some sort of photo viewing software included that will allow you to desaturate an image. The goal here isn't to create a final product or work of art, you just want to see what different scenes in different photos look like without color.
If you do this enough enough times, you'll start to get a sense of what you think looks good in black and white and what doesn't. You might find that you like close up portraits of people in black and white, or that photos with a lot of lines and shadows lend themselves well to black and white.
This has been a difficult task for me, to see a scene in color and try to imagine it accurately as black and white. I stumble on this, in trying to visualize different shades of red, yellow, green, blue, etc., as varying shades of gray. But there is a shortcut that can serve as a starting point for improving this skill: Look at a scene to see if it has both extremes, area(s) that are completely black or near black and area(s) that are completely white or near white.
Other key features to look for are shadows, lines and shapes. If a scene is strong in these areas, the odds improve in your favor for creating a strong black and white image.
It can also help to take a few test shots with the camera temporarily set to monochrome.
More and more cameras are offering an HDR (high dynamic range) option. This exagerates an image's dynamic range and can draw more attention to edges and texture. Cameras do this by bracketing the exposure of two or more images of the same scene and then merging them into one image. This can have the effect of drawing out detail that otherwise would have been lost in shadows, as well as detail that might have been washed out in the highlights of a scene.
Try shooting a few images from time to time with your camera's HDR setting and the converting the image, in post processing to black and white. If you find the end result to be too extreme, try setting your camera so that it takes and merges only two exposures rather than three or more.
If you don't have an HDR setting, that's fine, you can still try bracketing the exposure for two or more shots of the same scene and then merging those photos manually in post processing. For this, it helps to use a tripod and either a remote trigger or set the camera's timer. This will reduce camera shake and help make sure that the different images will overlap closely when they're merged into a single image.