Things aren't always black and white. They are shades of grey.
When looking into changing your photographs to black and white you actually have a variety of options. Photographers usually stick to one method. I've sort of fell in love with the first image below. A good balance between blacks, whites, and neutrals. If you've heard of 'BAMF' from Totally Rad Actions...I highly suggest you love it too. :)
The second image is plain old desaturated, which means all I did was remove all the color and boom...B&W. Notice a HUGE difference though don't you.
It's really personal preference. Which one do you like most?
