Fabric Workshop Library
   Illustrated step by step tutorial on replacing a slip seat cover.
   http://www.fabricworkshop.com/slipseat.htm

Kessels Upholstering: Do It Yourself
   Instructions for replacing missing buttons, recovering dining seats, and caring for furniture.
   http://www.kesselsupholstering.com/diy/diy.html

Vista Upholstery Enterprises
   How to information on various projects; including cutting and sewing, installing a zipper, and tying coil springs.
   http://www.upholster.com/howto/