I just want to say that this isnt really going to be detailed because the top build has said everything I was planning to type. The difference is our builds, which, in my opinion, work much better. Just remeber its all up to the user and how they play.

This will be my first guide on how to build any champion. I chose Ezreal because he is my mani, simply because he is so versitile and dangerous! This might not be the best guide but it surely is one hell of a guide!!! ENJOY

Some people may not agree with my rune selection, I can understand. But for me this works extremely well.
I like to use runes first as a bonus to my champion, then things they have flaws in.

This really speaks for itself. If you think something should be different, by all means change it up. Your the one playing him.

I first want to say that any person who is about to buy Ezreal, or use him for the first time, go AD (additional damage). Once your comfortable with him, and you have his skill shots down, I suggest practicing on AP (abilitiy power). So in future games, you study your enemies, decide which majority has less armor then magic resistance, or vise-versa, and use which build would help your team most. Thats why Ezreal is such a BOSS!
COMPARISON
Ap Ezreal has SO much more power late game, and Ad Ezreal early, sometimes mid game. I prefer AP Ezreal, simply because hes just a boss. Ex: After full build, your ult will do more then 1.2k of dmg. While AD Ezreal's only does 600-850
OFF TANK
Some people may disagree with the off tank, but this just proves how versitile he can be. Dealing major damage while taking some damage.
Everything really depends on how you build Ezreal. I dont suggest doing a hybrid between AD and AP. you just dont get that destructive damage you would with pure AD or AP.

Pros:
has nice range
extremely versatile
high dps
great passive
Pro champion
can take on almost any champion depending on build
hs built in flash

Cons:
Squichy if not building off tank (i doubt anybody would build this. But playing it like this is fun. :) )
cooldowns
mana goes by fast
if both your flash (ghost) and arcane shift are gone its hard to escape a gank.
no CC

Ap is hard to farm

This will be quick to get. Ad Ezreal farms extremely easy, while Ap is harder. Just remember, last hits are your best friend. Especially for AP Ezreal. Youll just have to wait till the minions hp is a little lower before attacking.

Best thing about Ezreal is his ult! If you good at predictions, you just became one of the deadliest champion, finisher, and KSer. Also for both AD and AP Ezreal, if enemies are at your turret, or lots of minions, send your ult there way. It has a low cooldown so nothing to worry about.
Also your essence flux is extremely helpful. While attacking a turret, baron, or inhibitor with teammates, its smart to shot them with it, giving them bonus attack speed. Use it whisely young one.

AD:
I like to use my Q (mystic shot), then follow it up by my W (Essece Flux). Hit them with a simple auto attack or two, then use your E (Arcane Shift) to get close. Hit them with a auto attack or two again, then quickly use Q then W again. If there getting away and have low HP thats when you shot your Ult. Just remember, your W is your best friend with AD Ezreal.
Early Game AD:
Its simple, last hit minions, and harass your opponent with getting in range with E, followed by a Q. Since your AD, you really dont want us W much becasue its just wasting mana for a skill shot that doesnt do much damage for you while AD (really it only goes for early game).

AP:
This is my favorite build when using Ezreal. Its probably the quickest way to kill an opponent with low Magic Res. You get in range with E (Arcane Shift)
followed by W (Essence Flux) then Q (Mystic Shot). Hit one or two auto attacks, then repeat. If an enemy is running with low hp...... ULT THEIR B*TCH ***! With over 1k dmg with ult with half a build, most enemies arent getting away!
I just want to tell you of a match that happened one day while I was playing AP Ezreal in the middle lane. I went up against Ahri. That right there was a victory for me. Two reasons: 1.) She is super squichy to abilities, and 2.) I can dodge all her shots with Arcane Shift. I followed my sequence of attack and she was dead in less then 5 hits.
Early Game AP:
Its a little more difficult to farm. But I think its easier to harass enemies. Esp with low magic res. You can shot your W through minions which is what really makes it better to harass. But you have less range.
Just remember, use your skill shots whisely. I usually only use them to harass enemies.

Easy really. Deal Major damage behind your teammates. Focus their damage dealer. And stay out of CC (Crowd Control) and enemy ability shots. You have range. Use it to your advantage.

Jungling with Ezreal. Never tried but there is a guide to it. Ganking though. Ganking is really easy with Ezreal. You hide in a bush. I usually wait till the enemy is past me. I use E (Arcane Shift) followed by (AD) Q or (AP) W, Then use which ever you didnt you. chase them hitting auto attack. Once your Arcane Shift comes back repeat attack order. Dont forget your ult :3

I hope this build is useful to anybody who usses it. Ive been playing Ezreal for over a year now. I can say with confidence that he is my main and i hope he will be yours too. He's simply awesome.
And riot..... MAKE HIS ESSENCE FLUX HEAL! Not attack speed... >:( anyways. Enjoy. and Happy Sniping!