Here's a few sites I found helpful:
http://www3.telus.net/drkrm/index.html (Black & White Darkroom Techniques)
http://photoinf.com/ (deals with composition mostly)
http://www.ephotozine.com/learn/ (they have some good articles...like printing with variable grade papers, etc).
I know it can be kind of 'hit & miss', but I found that if you "google" B&W photogaphy, then at the bottom of the page, pick "search within results" and enter 'technique' or another specific term it will help narrow the results.