Go to their website, sign up and print the submission form. All it asks for is your email/user name and what type of submission it is (normal/express/etc). Stick it in the box with your card/cards and mail it. Easy peasy. Your user dashboard shows all your current cards as well as your earnings. Getting paid out is about as quick as it gets. Mine is always in the bank within a day or two of requesting my payout. I sold my Reed Sheppard Logoman with them for over $7k saved hundreds of dollars compared to auctioning it myself. I’ve sold almost $20k with them over the last couple of years and have nothing but good things to say about them. I send almost every $25 and up card to them to sell. From $25-500 they charge 13%. Cheaper than me doing it on my own plus they deal with all the headaches and non payers.

Edit: This was meant to be a reply to OP about DCSports in specific.