Local craigslist, local community newspaper websites, Amazon.
Try backpage.com (similar to Craigslist).
Craigslist is the best.
I would sell it on craigslist.
Planetadvert UK http://uk.planetadvert.com/ or PlanetAdvert USA http://planetadvert.com/ depending on your location
I'm Trying To Sell My Mini Dirt Bike And Suzuki Minimoto Im Just Wondring What's A Good Website To Sell Them On(not ebay)?