This is my first Guide, it's about learning about Zeds mechanics and for people who want to master him. You'll learn builds, combos, how to use your shadows to their full extent, and most importantly, outplaying your opponents.

Youmuu's

If you chose black cleaver, and need a Youmuu's, for the speed and auto attack buffs, take it. (more of a mid game item, melees based on autos will fall off late)

Sword of the Occult

Only buy this if you can GUARANTEE that you will not die. Only buy this if the game is going to last up to 50 minutes, or it will be useless.

The Black Cleaver

If you chose youmuu's as your item previously, you can buy the BC as a situational aswell. It is incredible at taking down tanks and will help if your team is struggling to take down heavy tanks such as Maokai.

Mercurial Scimitar

Only guy this if you are against a heavy AP team, or a fed teemo. The active is incredibly useful in some situations and I highly recommend it.

Last Whisper

An amazing item. If you don't know what to buy, buy this. 35% armour pen, plus the armour pen from our runes will melt anyone who comes in range of your ult.

Zed is a difficult champion to learn, and even harder to master. You can carry with him, however, if your enemy is smart, they can easily counter you in champ select or with a QSS.

Pros:
He has a very high damage output
He has high mobility
He excels at taking out squishys in the middle of fights
He has incredible outplay potential
Hard to Gank
Great Roaming/Ganks

Cons:
Easily Countered
Hard to Learn
Hard to outplay and takes time to learn shadow placement/management
CC will kill him, he is squishy himself
Hard to get used to his kill potential

Zed excels at Farming, his passive does a percentage of your targets max health if they are below 50% health. This means you can clear faster and get more farm. Remember, if 2 or 3 minions are going to die at the same time, use your E. It does a lot of AOE damage. When you have your Tiamat you can clear entire waves with one AA to the melee minions, an E, and your Tiamats active. This also lets you split push

Farming Goals:
10 minutes = 90 CS
25 minutes = 225 CS
40 minutes = 275 CS

(By 25 minutes you should start roaming or team fighting and your CS will go down. If you are split pushing often from 25m-40m, try for 325 CS.)

Zed has some pretty amazing outplay potential, and you will need to know what to do when you are caught in a situation you shouldn't be in.
The 3 Basic Combos are:

-The Line:

You're gonna want to use this when your enemy laner is highly mobile, is over extended, has flash up, OR it is great for escaping in the jungle and getting a kill. For the Line, you are going to ult to your target, throw a shadow behind them, go to your W, and E. This will make the shadow you leave behind slow them. Now they will run towards you, or away. If they run away, simply go to your ult shadow which is now where they are headed. If they run towards you, Q, E and auto. You'll pick up an easy kill.
If you are using this to escape, ult to the target, W behind them, E, Q at them from your shadows, and run away. You should get the kill, if not a slow. If they cc you, simply go back to your ult shadow right before it runs out.

-

The Dodge:

Use this combo if your team is about to 5v5, ESPECIALLY if you are behind. With this combo it is easy to get kills in 1v3s or make a teamfight a lot easy for your team. Wait until their carry is a bit out of position, and if they aren't flash in (it's worth it). Then when they are in range of you, ult to them, Their team will see the mark and throw everything they have at you when you appear. So when you do, quickly throw a shadow diagonally away from their team. Then combo the squishy FAST making sure to land all your Skillshots and then quickly go back to ult shadow. When your e is up again, use it and your ult shadow will damage them a bit more. Remember: This is a lot of stuff to do, but you have to WWQER in under 1.5 seconds or else you will get stunned or die. BUT with practice, you will perfect it, and be able to successfully do this every time.

-Low Health Kills:

When you are low and an enemy is chasing or about to kill you, throw a W at them, and keep running for a second, then ult. Right when you appear go to your w shadow and combo them, then go to your ult, (they will run towards you, away from the ult shadow which you can escape to. When you go to your ult E. This may not always get you a kill if its a tank, but if its an AD Carry you will secure a kill. And kill or not, you should always escape if you do it right.

-Backwards Line:

This combo excels at tower diving. Make sure your enemy has no CC up, and then throw your shadow behind you, out of turret range, and ult at them. Land your skilldhots and E and go back to your ult, then W. (Your W will be out of range so you will need to go back to your ult first.

Eventually you will be making your own combos depending on the situation. You always want to be moving between shadows to confuse them if its a 2v1 or 3v1. You will want to also flash into a bush if the enemy is based on single target spells like GP or Teemo. Then you can full combo and kill the enemy

Zed is a very unique champion, with a high skill level if you want to carry with him. His outplay potential is amazing, however will take awhile to learn, this champion can send 3 abilities at once, something no other champion can do. Your ultimate is incredible at taking down squishys. Once you get used to his shadows and how to use them correctly, you can carry nearly every game with him. Aslong as you hit your skillshots you can destroy your enemies and hop from shadow to shadow every time they throw a skillshot, so that they take all the damage, and you take none.

To use your shadows to their full potential, you need to use them to not only dodge skillshots, but also single target. You also need them for your damage output. If you are against a champion, take Ahri or annie for example. When Annie uses her Q, ult. You cannot take damage or CC while ulting. This will take timing, but you will be able to dodge major CC and damage. If Ahri uses her charm, ult. After you ult you can throw down a W to dodge more abilities. Then you can throw your Q, use your E and you picked up a kill. Keep practicing dodges and hitting skillshots, and you'll master Zed, and carry every game you play.

When you use your Ultimate, make sure to land both Shurikens! Your shurikens are you main source of damage and if you don't land them they will not die, and your ult will be down, making you vulnerable. Make sure that if an enemy Carry is escaping a fight that you Shadow towards them, and Ult them, do your damage and get out. your shadow can help you go over walls to secure kills as well. DONT worry about Kill Stealing if no one can get the kill. If the tank or support is about to get a kill throw a Shuriken. You need kills, you need to get fed. That way your team can win.

Zed is an assassin who can take down squishys fast and effectively. Zed excels at mid game split pushing due to his high damage output. You always want a Tiamat so you can clear these lanes fast, and later build it into a Rav. Zed is good at taking out enemies when they least expect it, so running into the brush and then ulting will usually catch them off guard. Make sure to always catch people that are out of position and that you focus the squishy first.

Zed fits into nearly every team composition, so I wouldn't worry about that. He excels when playing with a Morgana as she is a heavy disengage just incase something goes wrong, or if your low and running from a high mobility champ, she can stun them so you escape. In Teamfights, never leave the safety of your tanks. YOU are the high priority target on your team. When you go down, you team has lost a huge chunk of damage output. Always play safe, with practice, you'll learn how much damage you can do, and know when its safe to go in and take out the AD Carry.

Remember: In Team Fights, always use "The Dodge" used in the Combos section of this guide. You will almost always win the fight, and lead your team to Victory.

Only pick zed if the enemy has already chosen a mid laner that does not counter you. Zed is a very easy champion to counter with LeBlanc, Malzahar, Azir and a lot of other ranged AP laners. I recommend this because once you get countered in your laning phase it is hard to pick yourself up. The only way Zed can carry is if he wins lane and gets high damage items FAST.