There are several methods to convert your color picture to a black and white picture. Check the following site for a nice Photoshop cheatsheet which shows you the black and white results of several settings. Check out the article on the original site on how to use the sheet. You can use your own photo in the sheet!
The download of the cheatsheet on that site seems to be a little slow, so you can download it here too.
There are some other nice cheatsheets on that site, go check it out!
Portrait Lighting Cheatsheet