Goodwill and Salvation Army stores (and yard sales) are great places to find used weights/mats/steps and fitness DVD's.

A REALLY great resourse for fitness DVD's is Collage Video. They have good prices, good shipping and excellent customer service. More importantly, they have excellent detailed reviews and previews of all their workouts, so it's a great place to do some research even if you buy elsewhere.

I was super fit before I bought my first road bike from using predominantly home workouts. There are some amazing workouts out there!