Xin Zhao is a great Melee DPS champion, and I love to use him. He has great early game damage, wonderful for setting up ganks and dealing damage very fast. Late game he is a very dependable carry, and if fed, can be devastating.

Pros
Great Close Range Fighter
Fast Damage
Has good health regen
Deal Massive damage in team fight
Great Duelist

Cons
Very Bad Without good Items
Bad against ranged
Can be countered by CC
Raped if No Mana Avalible
No Escape

Best Spells
Must Have:
Ghost
Exaust (Choose 2 Based on preferences)
Flash

I myself prefer to go ghost and flash with Xin Zhao. Flash can start and initiate a team fight, or help you escape from an enemy. Ghost Mostly Helps with chasing and escaping. Sometimes i also Use Exhaust because it helps with chasing down fast enemies to finish them off. All of these spells incorporate chasing, and escaping with Xin Zhao.

Alternatives
Ignite
Teleport
Clarity

Ignite can be a good Substitute because it can help finish off an early kill. From my experience, Ignite is not good for long term games.

Teleport can be useful in 5v5 to get around places and help your teammates out. Pick teleport only if you really have to, because you don't want to miss a kill because you substituted teleport for an important chasing/escape skill.

Cleanse is a good Alternative because it allows Xin Zhao to escape easier and survive longer, but his killing power becomes limited. It is extremely good to minimize your venerability to CC's.

No No's

Every other Summoning Spell

I built Xin Zhao's Offense to match his build, and so that he can carry. Defence is just to make him more tankey so he can survive longer.

Tireless Warrior

Tireless Warrior is the passive that heals you every three hits. This is a REALLY GOOD bonus early game, allowing you to get an edge on your opponent. You can also heal quickly in mid and late game because of your attack speed. Xin Zhao's passive also allows you to stay in lanes longer because you can just farm minions, and get your health back
Three Talon Strike

Talon strike is the first ability you pick during the game. It will go along very well with your other skills. It allows you to get three hits of bonus damage off your opponent, and knock them up in the air on the last strike allowing you to attack them more or allow a teammate yo come in and help you. Works well with Battle Cry because it allows you to get the hits in faster. Use this skill as much as you can because it is your main damage Dealer
Battle Cry

Battle cry has a great passive, giving you a 15% bonus attack speed at lvl 3! At later levels, it boosts your attack speed by 35%! Allowing you to have more attack speed without wasting item space. Its active is also great too, doubling your attack speed, and reducing your cooldowns by 1 second! At lvl 3 + 30% attack speed? Thank you! This, making battle cry harmonize with three talon strike very well, as well as cooling down your Ulti, and allowing you to use it more! But You have been warned, its passive disappears on cooldown. Good skill with low mana cost is worth investing in early game.
Audacious Charge

A great skill for starting a fight. It has a bit of a short range, but slows the area around where it was used. If your enemy is out of range of this skill but an enemy minion is near by, Charge it and it'll slow the champion even if you didn't target him or her with the charge! A great chasing skill also, allowing you to close the gap between you and the enemy. I Juggle this skill with three talon claw, holding off on battle cry while relying on items for attack speed. If it is a bad game, and you don't get fed well, you may want to think about putting some points in battle cry instead of charge for the extra Attack Speed.
Crescent Sweep

Your Ulti. It deals a flat base damage in an area and 20 % of the Enemies help. Insane. Extremely Good in a loosing team fight, as it can, if used correctly, get all enemies down to 80% of their current health. It also buffs your armor and magic armor allowing you to survive in a team fight. I recommend using this when at least 2-3 enemies are there to maximize damage output. Can be used for dueling if loosing, but not highly recommended.

Skill Sequence: Audacious chargee, Battle Cry, Three Talon Strike, then Crescent Sweep. If used right, can devastate a single or multiple targets.

Runes are highly based on offense. Trying to go with the build, attack speed and armor penetration are the most important in dealing the most damage. Cooldown Glyphs help to increase damage output in Xin Zhao.

Dagger
Dagger is obtained early game to get and edge on attack speed, and to help boost three talon strike and lead up to berserkers greaves

Berserkers Greaves
A great item for Xin Zhao increasing his attack speed for 25% as well as giving him a 2 movement speed that is badly needed. Works in harmony with three talon strike.

Black Cleaver
Black cleaver is one of the best items for Xin Zhao. It increases your attack by 55, and increases your attack speed by 30! Thats not all, the passive ability on this item shreds the target reducing its armor by 15! This item increases Xin Zhao's damage output to the max. Adding more damage to Three Talon Strike, as well as getting hits in faster and harder.

Phantom Dance
Great item for any Melee Champion. But for this build, is vitally needed. Increasing your attack speed by 55 isn't the best part, but it gives you a Wooping 15% movement speed, as well as adding in crit damage. This item is Crucial for Xin Zhao.

Last Whisper
This Item is debatable, but I like it personally because of its passive, which gives you 40% armor pen plus adding 40 attack damage. It really maximizes damage output, by allowing you to Bypass Armor easily. Great item.

Infinity Edge
This Last item is the compliment to all this build, adding 80 damage and increasing crit chance and making your crits 250%. Once you have all these items, you are virtually unstoppable. Have fun (:

Scenario Items
If you find yourself loosing or quickly dying, these items should help a bunch.

Randuins Oden
Also a fairly useful item for Xin Zhao, but is mainly used to help him survive. Adds 300 health and 75 Armor Resist making him fairly tanky. The active and the passive are also very good helping him to survive.

Force of Nature
Also a very good defensive item for xin, giving the most magic resist in the game. The regen is very helpful pairing with your passive, and a small bonus to movement speed of 8 is very good for helping him defend against spell-casters.

Guardian Angel
Especially helpful item giving you good amounts of Magic and Armor Resist. If you are going to get a defensive item, most if the time its going to be this. Obviously the best comes from its active, which revives you if you die, which makes the enemy Team Not Want to focus you but someone else instead

First Build Posted on here. Thanks for the feedback
Let Xin Zhao Dominate :D