There are several ways of completing a black & white photograph.
1st – you can do a black and white photography directly from your camera, through your camera settings. For example on my camera I can take black and white photos by going to my menu and changing the picture control to monochrome. This is only when you are shooting in JPEG
However, what I normally do is shoot in colour using RAW and than in editing switch to black & white.
You will need to have either photoshop or lightroom (there are free 30 day trials if you don’t have one)
The following PDF has alot of really great info for black and white conversion in Adobe Photoshop http://www.adobe.com/digitalimag/pdfs/phs8bwconversion.pdf
Jessica Sprague has an online class she is offering which includes a bonus turning your photos into black and white, you can sing up for the class here http://www.jessicasprague.com/index.php?page=shop.product_details&flypage=flypage.pbv.tabs.tpl&product_id=2367&category_id=40&option=com_virtuemart&Itemid=306
I will be posting later this week as I am hoping to do a variety of photos in black and white this week