I Need Organization Help

First organize things into a Keep and Sell pile. You have to be resolute about the things you're selling. If you live your day to day without it and it doesn't really hold any sentimental value then you need to sell it.

Once you have your pile of stuff to sell. Go through it and figure how much somebody would be willing to pay for it. Be reasonable. Some people wont see the value in something compared to how you see it. Mark up prices for items and try to keep a list of things you're selling.

Now you need to figure out HOW you want to sell your stuff. You can easily have your own yard sale, but if that's not an option look for local Sunday markets. There are often stands available to sell your stuff or boot sales to sell it directly from your car. Look at online options like eBay, etc

Another way of thinking it is this. You already got your money's worth out of the items in question. You already used up their value as far as you perceive which is why you want to get rid of them. If you no longer value them and all the above sounds too much work; just give it all to a charity. Their value will extend to other people. You may just as easily feel better by both clearing out all the stuff and by helping others in the process.