I remember, this was my tutorial when my lead had told me to practice writing some dummy device drivers as our team was supposed to merge into kernel team. Well, the merge didn't happen and this was my first and last device driver.

I liked the clarity and ease it offered to a first timer. I was somehow miffed about moving to kernel team from Java(app dev) but after this tut and some more articles I was disappointed when finally I didn't. This was one of the articles that changed my leaning towards learning C in a positive way. C is now my interview language :-).