To register on the account site click the register link.
Enter your email address, this should be the same email address you used when you registered for any of the API's. If you need to change your email on the API you can do this from links in the module or create a support ticket and a member of the support team will be able to help.
Once you have registered you will be emailed a secure password. Use this password to login.
If you forget your password it can only be reset by the support team. Please create a support ticket.