alt.smokers.pipes - this is a site connected to one of the most active groups on Usenet. Note that there's a comprehensive pipe shape chart.

smokersforums.org - excellent and very active forum. Great place to get advice.

The Gray Fox - this dude knows his stuff, especially about Kaywoodies. I'm proud to call him a good friend. His forum is one of the best.

Just For Him's pipe packing instructions - lots of background rationale for technique.

Tobacco Reviews - 2120 tobaccos, 7500 reviews and counting. Every major brand, every major blend. This is a major resource.