THIS GUIDE DOES NOT GUARANTEE VICTORY NOR DOES IT GUARANTEE GETTING A GOOD SCORE.
Have Fun! Remember that this is a game!
Xin Zhao can be built a number of ways, but I prefer him as a Glass Cannon assasin that darts into battles and hits them for huge amounts of damage.

Pros
-Major damage
-A Dash (only to non-allied unit)
-Knock up
-Percent AOE damage
-Great Ganker with dash that slows
Cons
-Uber Squishy
-Melee (doesn't really affect him...)

8-Attack Speed to for passive.
Greater Mark of Desolation1-Armour Penetration so attacks do more damage.
9-Armour for taking less damage in jungle and from AD champions.
9-Attack speed for faster jungling
Greater Quintessence of Desolation3-Armour Penetration so attacks do more damage.

9 Points in offence for armor penetration and attack speed.
12 Points in defense for armor, health and damage reflection.
9 Points in utility for move speed and improved buff duration.

Passive-A heal every 3 attacks, great with high attack speed
Q Spell-Buffs your next 3 attacks, third one knocks up. Casting will reset attack timer.
W Spell-Gives passive attack speed, on activate doubles passive and lowers cooldown of other spells for every attack. Three Talon Strike will apply the active.
E Spell-Dash to enemy dealing Area of Effect damage and slow. Can use on a minion near target to slow if the target is out of reach.
R Spell(Ultimate)-Swings spear to deal area of effect percent damage. Increases armour and magic resist of Xin Zhao for every champion hit. Great initiation move.

Starting with Three Talon Strike allows you to knock up jungle monsters to take less damage as it knocks them up. Also resets attack timer. At level 2 taking Battle Cry increases attack speed which increases jungle speed. Also reduces cooldown on spells so that you can use them again to deal more damage whether in the jungle or in the lanes. Taking Audacious Charge to improve your ganking and also can deal area of effect damage to jungle monsters. I max Audacious Charge first as it gives a slow and dash so that its harder for people to run away. I max Battle Cry next for the bonus attack speed. I max Three Talon Strike last as its cooldown remains the same and the damage is only increased by 15 per level.

The basic skill combo is Audacious Charge into Three Talon Strike while using Battle Cry for a faster knock up. However if your ultimate goal is to kill and not waste their summoner spells I would suggest walking up to them with Three Talon Strike and Battle Cry and when they get out of your range use Audacious Charge to catch back up while slowing them. Crescent Sweep is a great initiation move as it does percent physical damage to surrounding enemies plus a base amount. and buffs your armor and magic resist for each enemy champion hit.

I take Flash to catch up to my enemies and Smite for faster jungling and stealing of buffs that you have vision of.
Other Summoner Spells
Good alternative to Flash
A more aggressive player will take this over Flash. Leaves you with no escapes.
You have a passive heal, it works on turrets.
Xin Zhao will dominate, you won't die that often.
No defense or offense benefit from this spell when chasing or running away as they could use crowd control to stop you from teleporting away.
Good spell when it seems your getting focused, however running in after the other team is distracted by your teammates is a better idea than taking this.
You'll have blue buff, and if you don't so what?
For the super aggressive
Totally useless...for Xin Zhao
Already have attack speed boost
Good spell! Not for Xin Zhao though
A great alternative to ghost, however doesn't get you as far as ghost does.

Doran's Blade-Start with nice damage and lifesteal isn't really needed that much on Xin Zhao
Wriggle's Lantern-Faster jungling and wards
Berserker's Greaves-Suggested however I often take Boots of Swiftness so that I can gank more often
Sheen-Improves overall damage gives a bigger mana pool for a lower reliance on Blue
Black Cleaver-Shred to do more damage, also attack faster for a faster knock up
Trinity Force-Gives all around stats for an attack damage champion
Infinity Edge-Great damage and improves critical strike damage.
Phantom Dancer-Move speed, attack speed, critical strike chance
Bloodthirster-To replace Wriggle's Lantern but keep until next item is available.
Phantom Dancer-Same reason as other one, maxes out critical strike chance.

Increase Magic Resist, block spells. Great when your initiating into their whole team.
Increase jungle clear rate, taking bigger monsters faster. Black Cleaver does a pretty good job at that already.
Attacks slow on every hit so people don't get away, also gives quite a lot of hit points for durability.(Note: Trinity Force and Audacious Charge slow.
Decrease crowd control duration, increase survivability against magic damage champions.
More armor penetration, buff yourself for attack speed and move speed.
Cleanse put into an item, removes more debuffs than cleanse. Like suppression.
When they end up building hard armor, health and little to no magic resist. Demolish beefy champions with no magic resist.

All Ability Power items.

Three Talon Strike knocks up minions while slightly improving your attack damage and attack speed. Knock up those annoying super minions before they overrun your base.
Battle Cry has a low mana cost that instantly increases your attack speed to clear minions faster.
Audacious Charge does decent area of effect damage that can help clear a clump of minions.
Crescent Sweep clears minion waves easily, cool down isn't that long as you can use Battle Cry to shorten and have it before the next fight.
Smite instantly kills most minions.

Three Talon Strike knocks up monsters so that they are disabled for a short time, which may save you in some cases. Using Battle Cry will reduce the cool down of Three Talon Strike so that you may take even less damage with another knock up.
The route I take is Double Golem-Wraith-Wolves-Blue-Home/Invasion/Ganking-Double Golem-Wraith-Wolf-Red-Home/Invasion/Gank/Dragon-Double Golem-Wraith-Wolves
I use Smite on the double golems, the blue buff, and the red buff.
Remember as a jungler your job is to gank enemies or relieve a lane from an ally. If an ally is in need ignore the jungle!
Here is a map of the route. The purple side is the same route I just didn't label it.
Current Route for most of my junglers is Wolves-Blue-Wraiths-Wolves-Red-Golems-Anything else. Feel free to throw a gank in between camps.
Smite on Blue Buff and Red Buff for initial clear.
After the first clear Smite is open on all camps excluding wolves.

Xin Zhao is a great champion to take into a ranked game, with his amazing damage output and decent jungling. His ganks are ridiculously powerful. He is able to carry his team to victory in most scenarios.
Zoning tutorial by Shurelia. Play Video

1) Battle Cry reduces cool down of all your spells, so feel free to spam!
2) Challenge counts as a heal so it works on turrets.
3) Audacious Charge slows! Let your team catch up too.
4) Crescent Sweep buffs your armor and magic resist. If you are having trouble at a buff (like Baron Nashor) use it to decrease the damage you take.
5) Three Talon Strike KNOCK UP OP!
6)Mana costs so low. YAY!

1) Audacious Charge slows in an area, you don't have to hit directly.
2) Three Talon Strike doesn't have to have all 3 hits land on one target, you can hit twice on a minion and use the third strike to knock up an enemy champion.
3)The Area of Effect damage/slow from Audacious Charge and the damage from Crescent Sweep are the only abilities you have that can hit stealthed things.
4)Based on my understanding of Audacious Charge in its current form, it is impossible to get crowd control effects onto him. That does not mean he can take damage from the crowd control spell itself.

8/?/11-Started Making Guide
10/3/11-Guide Published
11/20/11-Update for Season 2 Mastery Tree
1/29/12-Tweaked Runes, Item Sequence, Mastery Tree, Skill Sequence, Added Scores, New Stat Screen. Changed Ghost to Flash, Changed Jungle Route