I have registered a domain name with godaddy.com, also I have rented out hosting space at Linode.com
Linode has given me a permanent IP. How do I link this IP to the domain name at godaddy.com ?
Linode has DNS servers and a well-documented DNS Manager application that you can use to create your own DNS zone and records.
To expand a bit on the answer by Steven Monai, you need to tell GoDaddy to use Linode's DNS servers to resolve the names for your domain. Then you need to configure Linode's DNS names for your domain appropriately. It might help to read up on how domains work so that you have more context for all of it to make sense.