Hello.

This is my first guide, but i am not a noob. I have been playing lol for about half a year now and i find that Kennen is a great champ for those players who want to have a great damage output trough the whole game. My Kennen build is a mid build, but you can use it top and bot lane.

Pros

High damage output
Good survivability
Good mobility and ganking
He is a flippin ninja

Cons

Early damage output is not that high
Cant have full ultimate potential if not farmed

I take my standard 21-6-3 masteries. But u can use those that suite your style.

I take the The usual ap masteries in the offense tree.
Next take 6 masteries in the defense tree. You will need the buff for your heal and some nice mres and armor.

In the utility tree take your good hands to reduce your time spent dead.

Thundering shuriken is your main poking ability. You will use this spell to add a mark of the storm to your opponent or to finish them off.

Electrical surge is your long range lightning. if your enemy has a mark of the storm u can use this ability to hit him and add another one.

Lightning rush is your go in/out ability. U will use it together with your electrical surge to farm minions. When you have lightning rush at lvl 4 and elec. surge at five you fill be able to kill the whole minion wave. Nice huh.That is not it.
If you pass trough an enemy while in lightning rush you will have some energy returned to you.

Your ultimate is a game changer. if you use it at the right place,at the right time, u will be able to stun the whole enemy team. This will leave them open for your allies to finish them off.

Start with dorans shield :it gives you some nice stat boost since you are squishy. Since you use energy you dont need any mana reg , but you do need hp reg. And it gives you some nice armor.

On your first recall you should have enough money for either hextech revolver or boots and an amplifying tome.
Before you finish your boots you must have your will of the ancients.
After that you will need your crystal scepter.It will give you a good mid-late game sustain. Next make your rabandon. this will boost your overall damage output.
now that you can score some kills you should buy a zonya hourglass.this will gove you damage and a smyll death resist buff(2 sec).
your last item should be a lich bane. Now befor you start flaming why a mana item , let me tell you something. You need lich bane for its passive ability.
Lets see: After you use an ability , your next attack will get bonus damage equal to 100% of your ap. And with all these items you should have around 650+ ap.
So you dont even need to land your q. Your autoattack is much more poverfull.

In team fights always go in last. enter the battle with your E and activate your ultimate.
Then quickly use your w to Huth their whole team. Last but not leaast use your q and autoattacks to finish off remaining enemies.

When farming use your e+w combo to kill the whole minion wave. Finis off remainigt creeps with q.

Heal-A great spell which will give you an advantage if you get focused. If a 1v1 is not going in your favour use heal and you will win for sure. And if your team gets low u can use heal to save their lives.

Ignite-Great ability to finish off a escaping enemy. Gives you some ap when on cd.

Flash-U can use flash if you want some escaping ability. I find it useless because of your lightning rush.

All other spells are useless on kennen.

I always play defensively until I hit lvl6. After i that i start playing agresively, and try to hurt my enemy as much as i can. When I get their hp to 2/3 or 1/2, I go in with my ultimate and secure my kill. When your enemy is dead or afk farm as much as you can to have that advantage. When you see your enemies regrouping go together with your team.
Wait for your tank to initiate, then go in with lightning rush and slicing maelestorm.
When the enemy team is disabled your ad carry shoud go in and finish them off.

Lux,Morgana,Ziggs,Ahri
After lvl 6 all these champs cant hurt you. You will have enough damage to push them back(recall). They wont get in your way of farming, and you will outfarm them.
All you need to do is to be agressive. Ward the brush so you can see incoming ganks.
This is the way you will win your lane.
Altough these champs are easy to play against, you must never let your guard down.
Avoid their skillshots and dont be affraid to get close.

Karthus - this R pressing bastard will keep you away from his minions and wont let you farm.
Ryze - you need to get close to farm and that is usually the range of his q. He will spam it ,a lot.
Cassiopeia - She is impossible to play against. You will need help from your team.
Heimerdinger - turrets,bombs,rockets. Do i need anything else to say.

This is my first guide so please rate it up. Sorry for any misspeling.I hope you will have a lot of fun with kennen. IF you have any suggestions and ideas please leave them in the comments.