Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This is an attack damage build for Urgot. It's probably the easiest way to play him, and I find it much more effective than hybrid builds.
First of all, Urgot is one of the best (if not THE best) harrassers in League of Legends. As soon as you hit level 2 you can start keeping your lane's enemies/enemy away from their precious minion kills. The basic combo is obviously Noxian Corrosive Charge(NCC) and Acid Hunter (AH). If you use it non-stop, you can get up to 3 hits from AH before NCC runs out. Obviously you're going to want focus the squishy opponent on your lane (although I do recommend asking to take the middle lane), since the tankier ones or the ones with health Quins aren't going to give a damn.
At level four you should have your Terror Capicitor (TC), if you've checked Urgot's skills you've noticed that only AH uses physical damage, so it's logical that TC won't be useful for it's shield, instead we'll be levelling it for it's slowing effect. During the eight second it's active every attacks of yours slows the target by an ammount that raises per level. This is great for chasing enemies, especially if you've hit them with NCC first. We level NCC last, since, again...this is an AD build and we only need it for it's targeting (although it's incredibly useful for farming late game).
I've already mentioned it. But you're going to want to harrass the squishiest oppenent on your lane. If you get a kill then great, if you don't then remember this - he now needs to go back to the base for some health. You're going to want to NOT spam your AH before you get Tear of Goddess, but once you do, spam as you please, remember that you need to use your skills 250 times, or hit 1000 times with auto-attacks (combining these two obviously also works) to reach Manamune's cap, so don't save your ammo. The more mana you have the more AD and health regeneration you'll have.
This is where you're NOT going to shine. Unless you aren't fed, you're probably not going to be the star of the show here. You'll barely do anything agains't tanks, and there are some DPSes that can destroy you. By this point I'm already buying parts for my Black Clever, once you get that you'll actually begin to do some damage, stacking 60 armor penetration (and adding the 30 from runes) means that tanks will actually watch out for you. Your best bet of course is to pick of lonely enemies, as you can hit them with NCC, turn your TC on and AH them to hell. Don't forget to use your ultimate to put enemies in the middle of Painsillvania by making them appear in front of turrets or four angry allies of yours. Your ultimate is actually the reason we're taking Flash. Once you make the switch you have two champions where they don't want to be, one might fall victim to your allies, but if you're quick enough you'll get out of there with a well timed Flash.
I'm going to be honest with you, I have finished this build twice. I usually don't have time and money to make everything, often leaving Yooumu's Ghostblade in Brutalizer form. Here you're either losing or winning, if it's the former then you're going to want to buy the elexirs(if you already have 6 items( but not Yooumu's Ghostblade), it might give you the boost needed to turnt the game around. Urgot is more of a early game champion, so even though you'll be doing massive damage your main goal it to slow and ulti enemies in your team's hands. If however you're winning you should get the ghostblade - the attack speed will help with solo and team inhibitor/tower pushing.
What is important for Urgot?
Urgot's cons are his low movement speed and squishiness ( if a tank build isn't used ).
To make up for the firt we take Flash and Ghost, to make up for the second you're going to need some training. Firstly, you'll want to stay behind your team, and spam your way into victory ( AH has a pretty long range even without HCC ), secondly don't solo. It is particularly bad for a character who isn't fast by nature to try and solo things like towers, dragon or anything else that might take a long time.
I hope this guide helps and I'll try to keep it up to date.