Porting a proprietary external DB format to a CCK custom node?

I am porting a website which used a set of PHP scripts with a MySQL DB to list links to sites of interests. The DB has a few fields such as URL, company it links to and a small text description.

I have made a CCK custom node name "mylinks" that more or less recreates the same fields I use in my old external DB.

Now the only step left is to migrate the old fields data to the CCK structure. What would you recommend?

My experience with Drupal is about a week so I'm pretty novice regarding developing using the Drupal API, etc.

Thank you for any leads you can provide.