So, if your looking at this build, then you have taken interest in Kennen. Let me first congratulate you on making a good choice. Kennen is a powerful top lane bully and is also a viable choice for mid. The single point to kennen that makes him so potent is his Ultimate, which allows mass stuns (if performed correctly) which allowing teammates to clean up without any other input from you. This guide will outline and describe an alternate way of building specifically your top lane kennen, and the thought process behind this build.

Pros

-Game changing Ultimate
-Good burst damage
-Great gap closing/ escape
-Fantastic farmer due to his Lightning rush, and ranged auto attacks
-Really good at harassing again due to poke and range

Cons

-Can be very squishy
-If shutdown early, difficult to recover
-High Priority in fights, due to potency
-without Zhonya's ult can be countered

Ignite- ignite on kennen is strong for the securing of kills, I would nearly always run ignite
Flash- Good escape, also great initiate with a "flash-ult combo"
Teleport- Fantastic for the top lane, allows for split pushing option (very prominent in current metagame)

Exhaust- This is down to preference, i feel exhaust is redundant, due to kennens stuns and gap closers
Ghost- personally I find ghost redundant due to your lightning rush, not that you cant run it, i just really wouldnt.
Heal- if you want it, take it. I am never going to recommend taking heal (as a side note, widely noted as the single best scaling summoner, but still, better not)

Revive- REALLY
Smite- ^^

Early game kind of makes or breaks Kennen (As with many champs). The most important things to remember early game especially are;

- YOU ARE A RANGED CHAMP, most of your top lane match ups will be against a melee champion. Abuse that factor: poke them and make them pay for every creep kill with damage.

- GET YOUR CS, the difference between a kennen on the team and a kennen making an impact is your items. Early CS = items = Potency. You want to be working on an early Zhonya's so you can ult and be happy. This build particularly will aid you in your csing because it does focus more on your auto attacks than most other kennen builds.