Zed is a very squishy champ early game. He is an easy mid champ but at the same time he can lose he lane just as easy. Try to poke them as much as possible. Do not over extend or push your lane to far, because junglers will get the easy gank.

Try to get as much farm as possible without pushing the lane. He is very easy to last hit with. If you do push your lane if your jungler is not around then you can take wraiths very easily.

With these iteams you will need to farm alot. Last hitting with zed is very easy because of his passive. Now if they do not have an ADC that is being fed i would trade thornmail for Lord Van Damm's Pillager.

Pros

Easy to farm with
He has a high ammout of damage
He can assassinate any alone champ
He has a massive amount of health
He's just bad ***!

Cons

2 people have no problem killing him
Has no CC
Very squishy early game

With this build you will need to auto attack more then use you abilities. I would engage with your W and then Q, E then proceed to tank their damage with your auto attacks. You will be able to kill most champs when they are alone. In team fights stay back, poke with your abilities and look for someone to fall out of position. While fighting Zed will gain a lot of his health back but not as much as ADC's.