Sewing on about.com - http://sewing.about.com/
SeamLyne's costume construction tips - http://www.seamlyne.com/design/costume/ GREAT page on fabrics and how to make things, including boots!
Suggested needles for fabrics - http://mrsews.com/lessons/lesson7.html
How-tos on various items including sewing - http://naughtyteaspoon.20m.com/HOWTO.html
Site on sewing and related - http://www.sewing.com/
Kwik-Sew's page on finding the correct pattern size and how to take measurements - http://www.kwiksew.com/techinfo/measure/measure.htm
Commercial site showing the various styles of sewing machine feet - http://www.ggcreations.com.au/althea/feet.html
Free online sewing book (VERY NICE!) - http://www.craftandfabriclinks.com/sewingbook/sewbook.html