Before you start selling, get all the headaches out of the way first -
AND GET PAID FOR IT!!!. First, open a bank account. Chase bank (and some others) offer a $100 to $200 bonus for opening a new bank account with direct deposit. Then open a second one for your spouse for another bonus. Then open a third business account for another $100 bonus. Use this account for your eBay business. Then sign up for a chase credit card for a $50 - $500 sign up bonus depending on the card you choose. Then do it again for your spouse. Finally get a business credit card for another $100 bonus for your new eBay business. You have just made $500 to $1000 even before you sold your first item. My wife and I have already done this and it only costs you one afternoon. Also use your credit cards for all eBay purchases,shipping supplies, shipping costs and earn cash back. Don't forget to pay off the balance in full each month or you will loose all your bonus money in interest over time.
Set up a spread sheet with an item description for everything you list, what you paid for the item, what you sold it for, what you charged for shipping, what the buyer paid for shipping and a total profit after you add all these together. At the end of each month, take your total profit from all items sold and then subtract all eBay fees from your monthly statement, all Paypal fees, all shipping related costs (boxes,tape,markers). This is your total profit for the month.
Don't forget to open a Paypal account and link it to your new Chase checking account. Almost all eBay payments are made through Paypal. You cannot successfully sell on eBay without Paypal.
Make a place to store your inventory. Make sure it is in a temperature controlled environment. The garage is not a good place. You do not want bugs, rodents, roaches,water moisture, to get in your valuable inventory.
Buy a decent digital camera (use your bank sign up money) You cannot sell without good photos.
I assume you already have a computer (otherwise you could not read this blog)
That's it! Headaches are out of the way and you have already made money!!!