You will often find information about pen and ink drawing, and there is certainly a a plethora of information about watercolor, but you seldom see mention of the meeting of the two.
Born in Japan, raised in the U.S. and now living in Tokyo, Russell Stutler is an artist who has a fascinating site devoted to his various interests, with an emphasis on sketching in pen and watercolor.
His Sketchbook covers 5 years and ranges from simple and quick subway sketches in pen to more elaborate drawings of buildings and streets, which are usually filled with watercolor washes.
His more recent and more finished drawings in particular are wonderful examples of that meeting of drawing and painting in which a pen sketch is painted into with watercolor and the pen lines “hold” the color, a style similar in may ways to traditional Japanese woodblock printing (see my posts about Hokusai, Yoshida and Hasui), and modern comic book illustration. There is a section of comics on his site, as well as some of his professional work.
The Sketchbook pages not only feature his sketches, but often versions of the same sketch in different stages (which I always enjoy) and his notes and comments on tools and techniques. Although not as elaborately extensive or organized as the handprint watercolor pages, this is still a great reference on tools and methods for the pen and watercolor approach to sketching. He has a nice list of recommended books with descriptions.
Stutler is a proponent of the waterbrush and there is a fascinating article about these terrific tools, as well as information about fountain pens and the interest in them in Tokyo in particular. He has also created a forum devoted to sketching and related topics, the intro page of which has links to additional articles about sketching and links to sketching artists and related sites.
Even if you’re not that interested in the tools and techniques aspect of his sketchbook entries (which are arranged a bit like a blog, but without dated entries), you’ll find some beautiful work among his sketches, particularly the most recent drawings of buildings, streets and storefronts in Tokyo, and houses, mills and other structures from his travels around Japan.