I start with Doran's Shield,HP potion and Warding Trinket.
Than I start rush The Blade Of The Ruined King. After that I built Mercury's Treads for Magic Resist. Lately we can buy Homeguard buff on them. After those two items we can build The Bloodthister for Lifesteal which is very helpful on Zed. After Bloodthister we will buy The Black Cleaver for HP and cooldown reduction. Than buy LW(Last Whisper). We have still space for one item so we can buy GA(Guardian Angel) or RH(Ravenous Hydra) but in the late game will be GA more helpful.

We can start with Q or E. Never start with W. I always start Zed with Q for bigger dmg. If u want to play more aggresivly we can chose W like a next spell for using double Q or we can play more safely and we can on the 2 lvl chose E for E,Q combo. Of course next spell choose W for using it like a flash if enemy jungler gank your line. Also we can use it for combo: Use W near to enemy, if enemy is close use E than quick Q again W to teleport to enemy and use Q again. On 4rd level max Q next level max again Q and on 6 level max R. Than i max Q and E mainly for big dmg.

I chose 21-9-0 for AS,AD,HP for flexibility on line.

Runes are little bit aggresive but its very powerful. I took AS Seals, AD Marks, HP regen Glyphs and AD Quint.

Try to use Q if enemy is near to poke him to his turret to free farming. Try as much as u can to last hit a cs. If u are on 3rd level and u has Q,W and E u can poke enemy very easy but watch out for enemy jungler. Watch out for ur shadow because u can very easy run away from both.