Here's a great source for cushion foam, polyester pillow forms, down cushions and custom made outdoor cushions in Sunbrella etc.
Thick, Dense Foam for Projects Can Be Expensive... Need a Cheaper Alternative? Use Crib Mattresses! Find out how in this tutorial! Great Idea.
Demonstration of how to cut upholstery foam with an electric knife.
PERFECT foam for dining chairs... High Density Upholstery Foam from Online Fabric Store
DIY Upholstery Supply - this site has tools, materials, supplies & fabric + videos, tips & a Q&A board. Great resource for the furniture DIY'er.
A step by step tutorial for a DIY padded headboard created using plywood, upholstery foam, and fabric.
CUSHION WORKS: Poly / Down Seat Cushion
how to cut and wrap foam for upholstery from charlebois fabrics
Upholstery Foam - More Than 25 Sizes of Upholstery Foam | DIY Upholstery Supply
Matrices.net How to make fur costumes and stuff