About the author: Hello, I am Js4400, and just wanted to share my Nami build with you.

Pros

Amazing at low level because of heal and stuns, will often get a teammate fed.
High base movement speed.

Cons

Squishy.
Runs out of mana quickly.

You want to get the mixture of scaling ability power and normal ability power so you can have a strong start, but still a strong finish. I think that 3 normal ability power and 6 scaling work best.