Before voting for this build (weather good or bad) I ask that you try it out IN-GAME first, before making any conclusions.

Hello, my name is ThePedoBear4 and this is my guide on how to play/build Warwick. I find that this build works almost 100% of the time, but the turnout is not always a win but you will definitely end up with a good amount of kills (unless your a really bad Warwick or you are new.) This build is also based off of attack speed and attack damage to make full use of his basic attacks and other abilities.

In this section of the build I will be explaining my reasoning for the runes I chose.
Greater Seal of Alacrity
I chose this rune for my Seals because I find that attack speed goes a LONG way with Warwick. Especially when used with his W, the attack speed increase is tremendous and can help put out a lot of damage in a short time.

Greater Glyph of Strength
The reasoning behind my choosing this for my glyphs is very simple, I play Warwick as an Attack Speed AD Carry. Although the Attack Damage increase isn't tremendous, it does well to have it early game especially to secure First Blood or maybe a couple of kills until you get deeper into your build.

Greater Mark of Desolation
I chose this rune because I found that when go against an armoured enemy, Warwick's damage output seems to "fall off the horse". By that I mean that his damage output seems to drop with every hit. So as a solution I chose Armor Penetration marks. NOTE: I you need more armor penetration to counter any massive armor on the enemy team feel free to switch the Sunfire Cape for a Last Whisper.

Greater Quintessence of Desolation
This rune is also for Armour Penetration, although it is not always needed I find that it would be helpful to have a counter to any armour, even slight amounts of armour from runes.

The masteries that I chose are pretty simple, I chose all the masteries that maximized my damage output and all the masteries that increased my armor and magic penetration. The reason I did this is to focus on the damage of Warick's basic attacks, and attacks from his Q and W.

This is a pretty important part of the build so listen to why I chose these items before you go about down-voting this guide.
Berserkers Greaves
For my choice of boots I chose Berserkers Greaves for the attack speed increase. I find that the attack speed increase help keep up the attack speed and damage output of your W and basic attacks until you can purchase a Phantom Dancer.

Phantom Dancer
I find that a Phantom Dancer is essential for Warwick to achieve a good score/kdr/game. The attack speed and movement speed increase is absolutely wonderful and ties in well with Warwick's W and E.

Frozen Mallet
During my games as Warwick I tend to be focused in my lane slightly more than my laning partner. Due to this fact I chose to wield a Frozen Mallet for two reason; one being the wonderful amount of health and attack damage it gives you, and the second being the slow it puts on players upon being hit. This slow really helps Warwick keep up with his enemy.

Sunfire Cape
This item is optional and can be switched out for any item of your choosing, weather it is a situational item or just an item you would rather have. I chose this item for the extra durability it gives Warwick as a champion, with an increase in health and armour on his side Warwick is even better in battle.

Guardian Angel
This item is also optional and can be changed for any item of your choosing. I chose this for the armour and magic resist increase, although you don't always need to worry about armour and magic resist it is a nice item to have.

Maw of Malmortius
I recommend that you keep this item but if you do with to exchange it for a different item I recommend switching it with a Malady or a Wit's End. I chose this item purely for the attack damage and magic resist, although the magic resist isn't needed and I haven't fully tried this item, I find that this item might be a good choice for some AD carries.

Passive:

Eternal Thirst
Warwick's passive is Eternal Thirst. This causes Warwick's attacks to deal an additional amount of magic damage and heal him for the same amount of damage he has put out.

Spell Q:

Hungering Strike
Hungering strike causes Warwick to heal for a certain amount after using this spell on target enemy minion or champion. I recommend maxing this out second because of the wonderful damage output but I would put it in second after his W.

Spell W:

Hunters Call
Hunters Call causes Warwick and nearby allies to receive increased attack speed when used. I recommend maxing this out first because of the massive attack speed increase which really helps put out massive amounts of damage.

Spell E:

Blood Scent
Blood Scent causes Warwick to go into a frenzy when nearby enemy champions are at less than 50% health, this causes him to gain increased movement speed when near wounded enemy champions.
I recommend maxing this out last because it has no damage output what so ever, and will be plenty effective when left at rank 1.

Ultimate:

Infinite Duress
Infinite Duress is Warwick's ultimate and causes Warwick to lunge at target enemy champion suppressing them for 1.8 seconds and damaging them at the same time. Like all ultimates you should be leveling this up at level 6,11 and 16. Although this is Warwick's ultimate it doesn't do massive amounts of damage but it does enough to secure the kill.

The summoner spells I chose are the default spells any offensive player should be choosing unless the situation requires different summoner spells.

Ignite

I chose this summoner spell to make sure that I get the kill when someone is low health and trying to escape.

Flash

Flash is an obvious spell to take on any champion for a quick method of escape. You might not necessarily need it on Warwick but it might come in handy.

Well this concludes my build, I hope you liked it and found it useful. Please give it +1 if you liked it :D

For ***** and giggles.