Check Earth911.com for information on how to ecologically dispose of items like fire extinguishers, fungicides, household cleaners, compact fluorescent light bulbs.
Usually local home furniture stores and mattress outlets will take old mattresses and discarded bed parts because the cotton, springs, foam can be recycled and given new life.
For old clothes Good will and Salvation Army are good options. According to organics.com you can use your cotton, wool, and old leather as compost.
For miscellaneous junk and items you never use consider craigslist and ebay. We recently had a 2 hour yard sale for a client who had died and got over $800 for the family.
Now more than ever, being green makes a difference.