The link at top on the right leads you to the according page. There you can set your email address and your password. Finally, you confirm your email by clicking the link in the email we send to your account.
Therefore, you click at top on the right on "register" and do the registration first in the usual way. After you registered an account, you have to verify your account in several steps.
The user name can be freely chosen. Nevertheless, the name might not contain a clue to real name or companies.
The registration takes only some minutes. After you set your email address and your password we'll send you a confirmation email. After you confirm the link your account will be activated immediately and you are able to create auctions.