Here are some of my favorite internet resources on haiku.
Haiku Resources and Techniques. Yeah, right, techniques. Yup, for Haiku. I know what you think, but even the shomon guys including Basho used lots of techniques.
HAIKU TECHNIQUES Jane Reichhold is one of the great articles on the resources site.
6000 Haiku of Issa. He really was a workaholic.
MSN-Mainichi Daily News: Haiku. Selected new Haiku from around the world.
The Five Hundred Essential Japanese Season Words. Because imho three lines with no kigo are no haiku.