Hello,
As wukong is a tank dps champion, who can easily own the game as he's a good early champion.
Well there's not much to talk about in introduction.

In this Guide i chose Armor penetration Marks, because wukong is mainly a AD champion http://www.mobafire.com/league-of-legends/rune-page-planner#&rune=300:1
About seals i chose seal of fortitude http://www.mobafire.com/league-of-legends/rune-page-planner#&rune=304:1 that will provide you a good boost in your hp at early game and helping with atmas impaler boost
for glyphs, glyph of vigor http://www.mobafire.com/league-of-legends/rune-page-planner#&rune=364:1 will provide you more regen per 5 sec increasing your survability.
For quintenses the same explanition of the marks.

For masteries i choose 21/0/9 so then you can have a good dmg boost and more exp and gold of utility mastery.

I first pick all of your abilities so then you can brust some more dmg and escape with your decoy.
After I master nimbus strike as in the early game (there are not much champions with much armor that's why i dont go for crushing blow first )that have a good dmg and also give you atk speed for 3 more seconds after the use of skill and survability as you can run away using this skill.
I master crushing blow and for final decoy.

HOW TO USE:

DECOY: This is in my opinion the best skill for wukong. You can harass enemies easily by using E>Q> then W so then the enemies will spent their skills on the copy.You can run from fights using it and runing for a bush or you can simply press
" S " as a simulation of your skill so then the enemies think that you used the skill.

CRUSHING BLOW: This skill is very good, as you have armor pen runes and black cleaver any champion with armor will be able to stop you. As it reduce the enemy armor by 30%. The dmg is Also high as it boost your basic atack.

NIMBUS STRIKE: Another good skill that will provide much as dmg and atk speed boost for 3 second after use.

STONE SKIN (PASSIVE): This passive is good but not excelent gives you a boost in your armor and magic resistance for each enemy champion nearby.Its not so significant but helps.

CYCLONE (ULTIMATE): Wukong's ultimate is VERY GOOD it knocks the enemy champions when wukong colide with them. you can use this ult for chasing, in ganks its very usefull as helps your teamates and have a good dmg, and also for runing... Yeah runing away as it knocks up the enemies.

For the spells I chose Flash and ignite just because with flash you can run and chase and ignite its a very good spells that can give you a first blood and helps you to finish an enemy champion giving more burst damage.
Spells that you can use:
FLASH same explanation above.
IGNITE same explanation above.
EXHAUST Thats a good spell you can use this for a first blood, for runing away and facing powerful ad enemies.
GHOST Another good spell good for chasing and runing away not my favorite but good.

ABOUT THE ITEMS:
- I first start with a doran's bladethat will give you healt, dmg and bit of lifesteal.
- Keep farming and rush a mercury treads http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=82 that's in my opinion the perfect boots for wukong as he gains tenacity so then he wont stay much longer on slows and stuns increasing his chance of kills and runing away.
- You can also buy some wards http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=33 or http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=100, that will help you much.Remember wards win games.
- Buy health potion http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=27 if you feel you need it.
- Rush a shen http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=55 as much as possible so then you can combo the dmg boost from shen with crushing blow; increasing your brust dmg.
- Finish a Trinity force http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=63 that's in my opinion the main item for wukong.
- After that you can for a Black cleaver http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=59 if you feel you need more dmg or a Warmogs http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=65 if you feel you need more suvability and healt.
- Built a Atmas http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=36 that will provide you a HUGE boost at your atk dmg, if you have warmogs this boost will be lot better.
- And for final Bloodthirster http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=60 giving you more AD and lifesteal. :)

SITUATIONAL ITEMS:

- Hexdrinker http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=112 against heavy AP champions
- Phantom Dancer http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=52 that will provide you a great atk speed and critical chance.
- Youmuu's ghostblade http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=101 giving you more AD armor pen of brutalizer and atk speed.
- I disagree with Frozen malet http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=41 just because you alredy have trinity force and you have 25% of chance of slowing the enemy about the healt that this provides well, that's good but the healt in this build is focused in Warmogs.

Try to last hit as much as possible and you'll farm really good when you have mastered nimbus strike then you can use nimbus in mages and last hit them with 1 hit, you can also use decoy and nimbus strike.
Sunfire cape is also a good choice but if think not the best considering that you have skills that will help you to farm very well.

Guys thanks for reading and please test it before rating, as it's my first build i apreciate any cometaries.
Also sorry for my english as i'm from brazil (:.
SEE YA!

WUKONG, THE MONKEY KING
sorry about the links of the images i just don't know how to put them =X