Hi, this is my first guide, so I hope you like it! I play Nami as an apc/supp. She is one of my favorite champions. So, I hope you liked it. Please leave a comment, or like (unless you didn't like it:) )

Pros

Stun is very reliable with some practice
Skills are spammable once u get chalice
Pretty good escaping, since all ur skills make u go faster
Very good for harassing, even in late game
Amazing ult
Good chasing

Cons

Very squishy if not played right
Virtually no 1v1 potential, as ur heal will keep u alive, but enemies just outdamage u
Relies a lot on landing ur q

The key too early game is harass, harass, harass. You got those mana pots for a reason. In the early game, practice throwing out your q. For some, like me, its pretty easy. If you are having a hard time, either stop using Nami, or practice in custom games. Once the enemy gets below half health, initiate with your q. watch out for the other supports stuns. Remember, if your adc is stunned, you can always e urself and ebb and flow the enemy. Nami synergyzes very well with Tristana.

Just follow ur bot lane partner around, but if ur too squishy, don't farm by urself.

Remember that u are pretty squishy, so I say u play like this.
Throw out ur q (and hit!)
Ebb and Flow the enemy (though you might want to cast it on ur allies, if they're getting low)
Cast Tidecallers' Blessing on ur adc.
Whenever a skill comes off cd, use it!
Oh, and stay behind ur allies at all times, except when ur casting a skill.