From what I hear, Craig's List is the best way to quickly unload your excess or unwanted stuff. Also, a good source for stuff you might need to furnish an empty room.
One thing to bear in mind is that your excess, old, or even antique furniture, however sentimentally-attached to it you might feel, is worth very little. Probably a tenth of what was paid for it. Brown-colored furniture (ie antiques or old stuff with dark-stained wood) is particularly undesirable. If you think it's worth $500, it might be saleable for $20-40 at best. Many people use Craig's just to get a few bucks to have somebody take it away because stuff has little value unless somebody wants/needs that exact thing at that exact moment.
Sell Your Furniture Online in 5 Simple Steps