While it is pretty difficult these days to get money by selling old electronics, there are are fews ways.
1.) Put them on eBay as a bundle package. This is very cheap for you to do, and it can earn you a few dollars you otherwise wouldn't have had.
2.) Put them on Craigs List- this is awesome because it involves local pickups, and it's a win-win situation; You get paid, and you're also recycling.
3.) While you won't get money, going to an electronic recycle drive is great for the environment and is much better than throwing them out. They host them sometimes near where I live, and tons of people show up.