You register for an account with ebay, which I believe now comes with registering with Paypal. Then you fill out a template and list. Don't forget to check shipping costs; depending on the size of the bag, it may fit in a USPS flat-rate box, the cheapest option. Remember to add in delivery confirmation cost as well; this is a must so you can prove the item got there. Also make sure you check where you agree to ship *to*- int'l shipping can get weird.
If it sells, ebay takes a portion of the sale once the buyer pays. The rest stays in your paypal account. You can transfer it to the bank account attached to your Paypal account, get a check cut and sent to you, or spend it like cash anyplace online that takes Paypal.
If you are a new seller with feedback of 0, your item will be harder to sell - and you may not want to go through all this for a single item. In that case, find a local place that will list for you. They'll charge a fee, but there's no hassle.
I would check to see if the item you are selling already exists on ebay and how much the seller is asking.
