The Xin Zhao character is a a good melee champ, who can easily pick out target like the enemies Adc or AP carry.
This Xin Zhao is played as the offtank jungle who can still deal out damage to the enemy team, but still survie thoughtout battles.

Just get the runes for more health so that you can survie the damage that you must take from the enemy team.
You will be the off tank and you need these runes, escpecially if the top is akali or a champ who hasn't got much health.

The masteries are for the subtain in the jungle against the non-monsters.
Even though that he has his Wthen he still needs some substain so that he can get thought the jungle fast and gank even faster.

Same as always:
http://edge2.mobafire.com/images/item/wriggles-lantern.gif for the life-steal and a little armor, plus you can clear the jungle faster.
[http://edge1.mobafire.com/images/item/mercurys-treads.gif] the standart shoes and upgrade it for the home guard editions so a quick start off the sporn.http://edge2.mobafire.com/images/item/enchantment-homeguard.gif
http://edge2.mobafire.com/images/item/the-black-cleaver.gif It is a great item for can break down the armor of an enemy champion. It also have some HP, CR and armor penetration.
http://edge2.mobafire.com/images/item/sunfire-cape.gif When you are the main man who needs to jump in the enemy team, the you need some armor and health. It also have the AoE effect for bonus damage.
http://edge2.mobafire.com/images/item/wits-end.gif The magic resist and attack speed is really great. You gain more Magic-resist as you attack an enemy champ and the attack speed + your W helps a lot.
http://edge2.mobafire.com/images/item/frozen-mallet.gif At last the Mallet for slowing down enemies and for some health and a little attack damage.

OMG LEARN IT YOURSELF!!!
Passive:http://edge2.mobafire.com/images/ability/xin-zhao-challenge.png
Q:http://edge1.mobafire.com/images/ability/xin-zhao-three-talon-strike.png
W:http://edge2.mobafire.com/images/ability/xin-zhao-battle-cry.png
E:http://edge2.mobafire.com/images/ability/xin-zhao-audacious-charge.png
R:http://edge2.mobafire.com/images/ability/xin-zhao-crescent-sweep.png

A way to gank the enemy top champ is to run in from behind, without him knowing.
Then use his Q http://edge1.mobafire.com/images/ability/xin-zhao-three-talon-strike.png and try for the knock-up and if he tries to escape then use your E http://edge2.mobafire.com/images/ability/xin-zhao-audacious-charge.png to close up the gap. If all goes well, then you end up with a kill.
The same stragery works for the mid-lane.
In the bot you need to pick out the champ with the less life or the one who cant get easy away from the fight. But this time you need to engage with the E http://edge2.mobafire.com/images/ability/xin-zhao-audacious-charge.png to close the gap and then use the Q http://edge1.mobafire.com/images/ability/xin-zhao-three-talon-strike.png for the knock-up and the kill.
You can jump into team-fights with the E and use R http://edge2.mobafire.com/images/ability/xin-zhao-crescent-sweep.png so that you can split the team away from the positions.