It is easier than you may think.
Online Auctions make the process a breeze.
Sign up for an account, take a few digital pictures, post it, and watch the buyers come to you.
A hint for selling brand name items is taking a few seconds to think, “If I wanted to buy this item, how would I search for it?”
If you do this, you will be much more successful.
Of course, some of your junk won’t be worth the effort of selling it online.
For that stuff – maybe garage sale, maybe just save yourself the hassle and give it to the thrift store.