Some domain name registries, often called network information centers (NIC), also function as registrars to end-users. The major generic top-level domain registries, such as for the com, net, org, info domains and others, use a registry-registrar model consisting of hundreds of domain name registrars (see lists at ICANN or VeriSign). In this method of management, the registry only manages the domain name database and the relationship with the registrars. The registrants (users of a domain name) are customers of the registrar, in some cases through additional layers of resellers.
Once you choose your provider, it's time for you to open an account with the monthly plan that fits your needs. If you still have questions about which plan is suitable for you, call its customer support staff and have them assist you through the registration process. Companies will generally charge a credit card on a monthly basis, however, some companies will also offer discounts for paying a yearly payment at once.