Instructions
Research each card and determine the approximate value. Search for the card on eBay to find out what it has sold for in the past.
Take a quality photo of each card. Use the macro function on a digital camera to get fine details. By using the macro function, you will avoid having to position the camera too close, causing a glare from the flash that obscures the card.
Grade your cards. Get high-value cards professionally graded by a company like Professional Sports Authenticator or Beckett Grading Services. If your card is fairly common, give it your own grade and disclose that you graded the card. Be fair in your grading, or poor eBay feedback will make buyers lose trust.
Write a description of each card that includes its detailed condition. Include the grade in the description.
Upload your photos and set a price for each card. If you think the price may go higher than your estimate, or the card is coveted, choose the auction format. If you want a specific price for the card, and want to sell it fast, use the fixed-price format.
Send the cards to your buyers. Place each card in a small plastic bag to protect it from moisture. Place the bag between two pieces of cardboard to keep it from getting bent. Secure the card in a box to keep it from moving around and becoming damaged.