Hello my name is ZoroDézu (or ZoroDark ingame) and i am the support from Kanjoyami Dominance (was Mid before). I want to show you my first guide on mobafire!
I am not that good in english and im not a highelo/hightier player, but i just want to show you my ways to get good with all existing champions. When you think you can't trust me cause i'm not in a high tier, do that. I can't judge you for that because i saw some idiots in the same div's i am atm.
Anyways have fun while reading this guide! I hope i'll help you.
PS. I don't really work to make this guide look good. I just want that the content fits :)

Welcome to the guide for the foxy lady! I didn't work that hard on this guide, but because i'm new to making guides i would like you to give me feedback why you voted this Ahri quide up/down.
Ahri is famous for her possibility to burst people down while beeing relative safe when she gets ganked. I hope you enjoy :)

Pros +ranged +Good poke with Orb of Deception +High Burst potential +Beautiful Crowd Control with Charm +Good roam champion +Very good initiate or escape with Spirit Rush

Cons -Squishy -Needs spellvamp or blue buff to sustain poke -You can easily outplay yourself with Spirit Rush -Mana hungry early -Silence=Death

Standard AP

//Go the standard ap 21-0-9 in standard situations. The Sorcerywill help you in lane a lot while Blast Mental Force and Archmage are awesome on every ap champion! You'll also benefit of having Meditation cause this extra mana can save your life

MARKS!
Greater Mark of Magic Penetration are the only one you want to make as Ahri.
If you however want to play asap Ahri jungle like my friend DasGabelxD, get Greater Mark of Attack Speed for better clearing.
SEALS!
Here i prefer Greater Seal of Mana Regeneration when you want to have sustain with your passive and harder poke or for jungling.
You can also go Greater Seal of Armor against AD mid or for a save early game.
Greater Seal of Health will grand you a better tankiness early and are helpful vs champions like Cassiopeia or Orianna that poke you hard at the begin.
I once saw a seal combo with Greater Seal of Health Regeneration and Greater Seal of Mana Regeneration so if you want to try it, give it a shot :)
GLYPHS!
Very easy to understand :)
Go Greater Glyph of Magic Resistfor a standard matchup, Greater Glyph of Scaling Magic Resistwhen you think you want to roam alot and Greater Glyph of Scaling Ability Power when you think you win your lane :D
QUINTS!
Always go Greater Quintessence of Ability Power for higher damage output. There's no reason to not going ap in quints ;)

This is how I think about S. Spells! Important and situational S. spells are chosen from own gameplay.

Always take flash with Ahri. It is the best spell in the game.
Here you have your choice. Figure out with what you are the most comfurtable but try all 4 spells out! I prefer ignite vs. squishy champion and Master Yi, Barrier against Lux etc. and exhaust against ad mid.
I don't really like all this spells since i don't go Ahri jungle and i think Heal is just a bad spell in S3!

This is how I think about items! Items are chosen from own experiences.
Items that are in one of the builds will not get listed!
Archangel's Staff
Ahri is a ranged Ap assasin. I think this item is a waste to buy, because as Ahri you don't want to have much mana like Ryze or Anivia.
Banner of Command
This is a support or early game item. But it's not strong enough to think about getting it though.
Doran's Ring
It's ok to buy some Doran's Ring's when you don't have the gold for going other items.
You get stronger early and mid game with Doran's Ring but you get weaker last game.
However don't get more then 2 Doran's Ring's and it would be the best if you go 1 Doran's Ring maximum.
Iceborn Gauntlet
Have you ever read the passive? This item is oonly something for hybrid's or blue build Ezreal
Hextech Gunblade
I see no reason to get this item.
Morellonomicon
When you like this item, get it! It fits very very good on what you're gonna need. CDR, ManaReg and Ap? HELL YEAH!
However i think Athene's Unholy Grail is still 1% better then this item.
But it's still very good and viable! :D
Ohmwrecker
Well this item gives health, ap and regens. Just from the stats, this is a good item for Ahri. But i don't know how good. If you are good with effect items like Deathfire Grasp and think you'll lose your game, you can start with Kage's lucky pick and philosopher's stone to get some money!
Shard of true ice
Just don't go for it, it's way better on supps.
Twin Shadows
I think this is not worth it with Ahri, because you would need to sell it later.

ONLY DIIFFICULTIES UNTIL ALL MY OTHER GUIDES ARE FINISHED UP TO THIS POINT!
This is how I think about the matchups! Difficulties are chosen from own gameplay with/vs. Ahri.
difficulties are 0.5/10!
difficulty:5 Dodge skillshots! Deny farm!
difficulty:8 Beat her early game! Try to roam! Only Spirit Rush after you Charmed her so she can't Shadow Dance to you! Maybe ask for laneswitch, when you were good vs. her early.
difficulty:4 Dodge skillshots! Buy Mercury's Threads! Try to deny blue for her! Ask your jungler to gank early game! Rebirth
difficulty:10 Ask for lane switch! Stay out of range! Pay attention to her stun! Roam as much as possible! Keep her away from your adc!
difficulty:4.5 Dodge skills! Just try to get more gold then him! Try to win trades! Land your combos!
difficulty:3.5 Disengage when poissoned! Deny blue! Dodge her skills! Care for enemies ganking you!
difficulty:5.5 Dodge Q! Ask for ganks! Deny Feast stacks! Deny farm! Poke him hard!
difficulty:9 Ask for lane switch! Dodge Q! Push her to the tower! Don't let her get your adc! Don't run into her Pale Cascade!
difficulty:6.5 Try to dodge her E/Human! Play aggressive when she farms in Spider Form!
WILL BE COMPLETED ON 8.6.2013

First: I know you'll thinkWHAT FOR AN IDIOT WOULD GO CHARM LVL 1
Now...think about it :)
In the very early game your auto-attacks hurt very much!
When you hit a charm you will be able to get 2 auto-attacks on your enemy and that is very high damage!
However: Don't pull the blue or red with charm! That will cause the blue or red to regen hp which is a bad pull :(
Max as follows:
Vs. normal opponent
>> >> >>
Vs. very mobile opponent
>> >> >>
Spirit Rush is a very good ult. There is no point to not maxing it as fast as poosible
Orb of Deception is a good scaling Ap damage poke with medium range. It is your main damage output and should also be combined with your passive as much as possible
Fox-Fire is a relative good scaling unique ability with makes 3x damage but the dmg has a cap at ~200% dmg when multiple flames hit one target.
Charm is your hard Crowd Control ability. It is usefull to start combos but has too high cooldown and to low scaling to get important in maxing.
This is Ahri's passive. This passive won't be game changing but it's still important to know when it's ready. When you push (don't forget the Sight Ward's!), or when you are not full health use it with your Orb of Deception on a full minion wave and never waste this on your Charm
This is Ahri's Q and her most important ability pre 6 . It deals magic and true dmg when it comes back. This means enemies that stacked tons of MR will cry until they surrender. It has not the highest range but still outranges many other abilities in the league.
This is Ahri's W and her most important ability against high mobile champions. It has low Cooldown Late Game and medium range. I max this when i play against Katarina, Akali etc. It works better after hitting a Charm to have a little AND easy combo.
This is Ahri's E and her most important ability for combos. It is a long range taunt which also damages the enemy. That might be the best fitting ability for Ahri when we look at all things pro can make with it. Try to charm a important target in a teamfight and you won't get sad in the next 15 seconds.
This is Ahri's R and her fun assasin part in her kit. It's an damaging like Arcane Shift but you can activate it 3 times. Don't over extend with this ability. It makes damage BUT can be used very bad.
How a bad Spirit Rush works!
-set's you near to enemy's Crowd Control
-only dealt damage to the tanks
let you look like a Ahri first timer
-isn't used for engage or escape, only for damage
how a good Spirit Rush looks like!
+you are still in a good position after you used your Spirit Rush's
+makes you ready you kill the Ezreal or whatever you're facing at
+moves you away from Crowd Control possabilities
+let you look like a StarCraft player
+ is used for the best engage or escape possible