I have a ton of stuff (junk) in my garage and I am wondering should I juts throw it all away or there is a way to actually sell it and make some money?
1. Get a list of the things you want to sell
2. Get a list of websites to list them (ebay, classifieds, forums etc.)
3. Take extensive and nice photos (and even videos)
4. Create very good descriptions of each product
5. List them
You'll probably get good response if you put the effort into this.
You can make your trash into treasure by selling your useless things online or offline and if you sell your trash or useless things at good rates then enjoy the profit and try to invest in good things.
There's a way of turning waste organic matter into electricity that is already in use, so for instance a Nestle factory in Newcastle (UK) produces 5% of its energy needs by processing it's own waste candy this way. That is Anaerobic Digestion where bacteria digest the waste and produces gas as a result, the gas is burnt to generate electricity.