First, you need an Auctionet.com account. If you haven't got one already, sign up free of charge. This is the same account you can also use to place bids.
Next, this account must be associated with your sales. Visit the page Seller accounts (part of "My pages") and follow the instructions. You will receive an email with a link. Click that link and you're done.
Once this is done, you will find your sales, contracts and payouts on My pages under the header "Selling items".