Selling online takes a bit of work and some practice, but it's not too hard. In almost 10 years of online selling, I can't think of any bad transactions (more than 30 sales, but I don't have an accurate count) Amazon is the easiest because there's almost no work required on your part. Ebay is more work because you have to create a listing, etc, but you can sell just about anything and get a good price for it. Craigslist is OK if you don't mind dealing with people locally.
My favorite way to get rid of stuff is Freecycle. If there's an active Freecycle group in your area, you can give away stuff that would generally have very little value, but it's valued by the people who want it. For example, I've given away half a bag of charcoal, most of a pack of photo paper, an old electric kettle, old computer speakers, and similar things that aren't worth selling.
I really hate throwing stuff out, so I generally won't get rid of anything unless it goes to someone else, or I can recycle it.
You could also list stuff in the Mustachian Marketplace subforum. If you only sell to people who have an established history on the forum it should be a low risk way to get started. It's a small market, though, so you might have more success elsewhere.
One benefit of being good at online selling is what I like to call the "ebay rental service". You can buy anything to use for a while and resell it for a wash or a profit.