Hey, this is my first guide, so please try to be nice, I started playing LoL in april 2011, I didn't enjoy any champion that much, but I kept on searching, once I bought Akali I was amazed, I've been playing Akali for 2-3 months now and I still enjoy playing her! This guide is not finished, it is not even near finished, I will also update this guide after every patch, or if I find an improvement to an item.

To take full advantage of this guide go top lane so it's easier to farm minions!

Pros:

Fun to play
Crazy damage
Good ganker

Cons:

Squishey
Akali gets focused a lot in team fights because of her damage.

16/10/11 - Added a Crescent Slash tip, added 3 items to 'Other Great Items for Akali', added a tip to the 'Introduction' chapter of how to take full advantage of this guide.

07/11/11 - Removed Rod of Ages from 'Other Great Items for Akali', I don't even know why I put it there, mana is useless for Akali, added Sorcers's Shoes to 'Other Great Items for Akali', changed explanation on Ghost in the 'Summoner Spells' Chapter.

The runes I have chosen for Akali is self explanatory.

Greater Mark of Attack Damagex9 - The reason I use Strength (AD) marks is to give my auto attacks that little more push, Akali does very low damage to turrets, and tanky champions so a little Strength is always good.

Greater Seal of Vitalityx9 - The reason I use vitality (Health per level) runes is to make Akali that little bit more tough to kill, Akali is a squishy champion and I find myself coming out of fights with very low HP if all of my abilities we're on cooldown, these Health Seals could also save you from DoTS (Damage Over Time).

Greater Glyph of Scaling Ability Powerx5 - The reason I use Force (AP per level) glyphs is to increase Akali's damage, these are very effective and help most at higher levels.

Greater Glyph of Ability Powerx4 The reason I use Potency (AP) glyphs is to make your damage stand out from others at low level, these are flat runes so do not increase their effectiveness at each level, but they do make your more powerful at lower levels.

Greater Quintessence of Ability Powerx3 - I use Potency Quints to give my damage that extra push it needs, not much explanation is needed here.

For my masteries I go 21 in offensive tree to make Akali's damage excell from others, I also go 9 in utility to be able to level up faster (Awareness), I also go 9 in utility for the 9% less time spent dead, this is very helpful when you aren't doing so well, it also helps you when you die anyway!

Mercury's Treads - These are very helpful for Akali, in my view they are the best boots for her, this is because Akali is very movement dependant so these boots help from Akali getting CC'ed too much, these could also save your from ganks, and they could also help you stop enemy champions from running away.

Rylai's Crystal Scepter - I get this item in almost every game I play with Akali, this is because it gives you a good amount of AP whilst giving you some extra health for protection, this is also a very good item for Akali because of the passive, the passive slows on enemy by 35% for 1.5 seconds, this is very helpful because Akali doesn't have a slow of her own.

Rabadon's Deathcap - This is one of the most important items for Akali, this is because of the huge about of AP it gives (140), also the passive increases your AP by 30%, this hugely increases the damage output of Akali.

Hextech Gunblade - This is a very useful item for Akali, as Akali is usually played a hybrid she benefits massively off AP and AD, the 20% Lifesteal and 25% Spell Vamp also help, the Unique Active from this item also helps Akali a lot, it Deals 300 magic damage and slows the target champion by 50% for 3 seconds, this is helpful because Akali doesn't have a slow of her own, this could also be used to finish off enemy that are at range.

Void Staff - I usually use this item in my build when I'm playing Akali, it mostly help to kill tanks that are stacking Magic Resist, the extra AP + Spell Vamp also help increase damage and surivability.

Guardian Angel - I use this in my build around 60% of the time, it is most helpful when the enemy team is focusing you, if I don't buy this I would usually buy Lich Bane because it gives you a lovely amount of AP, extra Magic Resistance and it makes your first auto attack after you use an ability hit like a truck, the only time I wouldn't but Guardian Angel is when I'm not being focused.

For my Skill sequence I would usually level up 'Mark of The Assasin' and 'Crescent Slash', but I would also get 1 point in Twilight Shroud for protection, I would also level up my ultimate whenever possible.

Rotation - To start my rotation when ganking I would use Mark of The Assasin, and then jump to the target using Shadow dance, then use Crescent Slash, keep in mind that using Crescent Slash against fast moving targets is likely to miss.

My rotation for a gank would go like this; Q-R-E-Q-W-R-E-Q, and so on.

NOTE: Crescent Slash can be dodged by fast moving champions.

Flash - For Akali Flash is a must, when your Shadow Dance has no more uses it help you get to an enemy target, it can also be used to jump out of ganks, Flash is a life saver!

Ignite - I usually use Ignite for Akali, this is to finish off enemy champions that are on low health, when starting a gank dont waste ignite when the enemy champion is still on high health, this could mean you wasting it. It is most useful when an enemy champion is on low health and running back to their turret.

Other Summoner Spells the are good with Akali:

Exhaust - As Akali has no slow of her own Exhaust is very helpful, it can also turn fights around because of the damage reduction the target you cast it on gets.

Ghost - Ghost is helpful for low level summoners, this can also get you out of ganks, because of the increase in movement speed, because of the increase in movement speed it can also help you catch up to escaping enemies.

Akali can be a very good farmer, Crescent Slash is her farming ability because of the AoE, also if you are using Spell Vamp Akali is a more than capable jungler, other then that there isn't much to say about Akali's farming abilities.

Lich Bane - 9/10, This is also a very good item for Akali, it gives you lots of Ability Power to hit like a truck! It also gives you a little Magic resistance that could save you many times, the extra 7% movement speed is very handy.

Zhonya's Hourglass 8/10, This item is good for Akali, it gives you very nice amount of Ability Power, the armour is also helpful for fighting physical damage based Champions, the 'Unique Active: Places your champion into Stasis for 2 seconds, rendering you invulnerable and untargetable but unable to take any actions. 90 second cooldown.' can be life saving in fights, useful for when you are low on HP and the enemy is tower diving to try and kill you, also helpful in team fights if you are getting focused, remember you are not able to move or cast any spells whilst the spell is active.

Boots of Swiftness 7/10, Good for catching runners, but I still use Mercury's Treads almost every game because of the Tenacy.

Trinity Force 8/10, Good all around item, quite over priced though, I would only buy it if I am dominating.
Sorcers's Shoes 8/10 - These boots are a great pick if your not planning on buying Void Staff because they give you 20 Magic Pen.

When playing Akali you need to think, you can't just go straight into a fight, you need to think about how many charges you have on your Shadow Dance, your current energy and if your target is tanky, Akali excels at nuking targets which are squishy, if in a team fight target the most squishy champion first.

Keep in mind that Twilight Shroud can slow enemy, most people who play Akali just use it for the stealth, other things to think about when using Twilight Shroud is that are there any brushes near I could use to juke an enemy? am I surrounded by enemy champions?.

Other things to think about in general when playing Akali is to think how far away an enemy turret is when ganking, you also need to remember to use your Unique Active from Hextech Gunblade to slow the enemy, this could stop your target from reaching their turret in time.

Thanks for reading, please post in the comment any improvements or mistakes, I will try as test anything you suggest!