Hello everyone, this is my first guide!
I played zilean for quite long as my main and i wanted to write something down for players that are new to him.
This is not meant for any experienced or pro player.

For this build i have in mind a more aggressive early game play style.
Zilean's bombs are pretty amazing and if used correctley you can blow up anyone (almost).

Hope you are gonna find this usefull.

With any doubt flash and clarity have on zil the best utility.

While flash with your E can make you escape almost everything, Clarity will give you more early game sustain( with the result of more bomb spamming).
If you still find yourself finishing mana i can suggest switching the yellow ap flat runes for the mp5 ones.

Other choices can be:
ignite (but you probably have to take "summoner's wrath" for the 10 extra APs"
Teleport (if you wanna be some sort of improved shen combined with your ulti)(or also for fast cleaning a lane that is pushed)

I don't suggest anything else with this setup.

The masteries that you can see above are meant to be for an aggressive early game (as i said before).
So you are not really a support but still can do.
Zilean supporting consist mostly in his E and his Ulti.
Obviously you are gonna need some wards around too.
Don't be afraid of spending some money on wards,they are not usefull, they are NECESSARY.
The lack of clairvoyance should be replaced with more warding around.

Do you really need a guide for farming with zilean?
Just Q -> W -> Q the minions in the center of the wave and all creeps will be blowed up.

Btw i don't recommend playing with an AD carry bottom lane or you are gonna steal eachoters farm. This is the major reason that this guide isn't really meant for supporting but more for fun.

No farm mean no items, Gp10 items mean no damage. No damage with this setup mean you are useless.

I'm gonna finish this guide sooner or later, but there is not much i can tell you.