It's crucial to keep track of where you registered your domain name and the login information needed to access it. (If you have a brick and mortar store, you wouldn't forget where to send your rent or mortgage payment.) Also make sure the contact information the registrar has on file for you is always up to date, especially your email address. This helps avoid your domain name expiring or paying a fraudulent domain name renewal "bill" from another registrar and losing control of your domain.