Calligraphy Centre on What is Calligraphy?
You'll find an excellent introduction to the forms and techniques of calligraphy, including some beautiful examples.
This article by Siu-Leung Lee focuses on describing the history and signficance of Chinese calligraphy. It includes a brief discussion of Western artists who were influenced by the art of beautiful writing.
Jun Shan (About's Guide to Chinese Culture) has written a delightful feature about the importance of calligraphy in China. The page includes links to a beautiful collection of Chinese calligraphy.
Letter Arts Review
This online magazine is devoted to calligraphy and calligraphers. The articles, competition announcements, and images of calligraphic works all make this site both relevant and interesting.