Welcome to my first build starring Urgot. Urgot is a great physical dps champion, and requires some skill to get used to at first. Upon getting used to him, you will never lose again. Here are some screen shots of me.[Note: I was trying out trinity force in those matches, it worked out okay but i wouldn't recommend it.]

The reason for not getting boots before buildingis because you want the extra mana regen to harass harder(you harass a lot), to get the early mana for, and because you have a slow and a shield so running away without boots shouldn't be a problem. Also not to mention flash and ghost.
Are ideal for ANY champion in my opinion. The reduced CC duration will help you a lot in many situations, and the magic resist is nice too. If you find that you aren't getting CC'd very much, or the other team isn't doing AP, then gettingwould be another option due to Urgots low base speed.
Manamune is a great item for Urgot. By the time anything major is happening, you will have a big enough mana pool to basically spam anything you've got, and you get increased attack damage with it.
Brutalizer is also an excellent option for Urgot. This will give you nice attack damage, and cdr. The CDR will help you for when you miss your Noxian-Corrosive Charge, and have to wait a bit to try and reapply it. This will also help with your ultimates cool down(Around 100seconds with brutalizer)
The bread and butter of Urgot. Last Whispers armor penetration makes it an amazing item for Urgot. His Acid Hunter will penetrate armor with this, making you do devastating damage
Bloodthirsters attack damage is amazing. This will just make you do insane damage after you buy it. The lifesteal is nice as well.
Phantom Dancer should be bought last. The reason for it is for the increased movement speed mostly. Put the attack speed and crit can be nice for when you happen to be out of mana or for when you are farming. Sometimes you may even get away with auto attacking someone who isn't focusing you, and just destroy them with your already obtained ad.
Guardians Angel will be key to you not dying a lot. By late game you've already been harassing many people, and they WILL hate you for this. This will leave you being focused a lot. Sometimes you wont even die, but the piece of mind that guardian gives keeps you doing good and not dying.
Banshee's Veil is excellent against CCers or Casters. A must have by late game.

Acid hunter is your main damage ability, and it scales with attack damage, not ability power.

Urgot fires a missile towards the cursor location(this is key to mastering urgot not a target location.) dealing physical damage.
It also applies your passive. If someone is effected with noxian corrosive charge, and your cursor is on that target, it will home in on them hitting them every time.
Terror capacitor provides urgot with a shield, the damage absorbed scales with ability power.

The shield is not very effective, but when it is on, your autoattacks and acid hunter slow the target.
Noxian Corrosive Charge deals damage over time scaling with attack damage, and get reduced armor.

Enemies who have the debuff on them get targeted, and if you use acid hunter with your cursor over them they will get hit every time. You will be using this combined with acid hunter almost all the time.
Urgot gains bonus armor and magic resistance for 5 seconds. The target is stunned and suppressed for the duration of the 1 second channel before swapping positions with Urgot. After the swap, the target is slowed by 40% for 3 seconds.

This ultimate has a lot of possibilities and is my most favorite in the game.

Your basic skill sequence will be this most of the time:

Noxian-Corrosive charge > Terror Capacitor > Acid hunter spam and autoattacks > repeat.

You will be praised for using your ultimate correctly, and then despised for using it wrong.
Here are some tips for using it.

You'll want to save it for someone who is running, or someone who is too close(Excluding tanks)
If they are running, you need to ghost, and if necessary, flash to the target and swap them into your team. If you are chasing alone, swap them behind you, turn on your shield, and turn around and nuke them. Since your shield is on you will be slowing them.

Teamfights:
When you are in a teamfight, the timing of your ultimate is key.
You can use it to swap in carries, but beware of positioning. You do not want to swap yourself into the enemy team and get mowed down. Remember that your ultimate stuns people as well. If someone gets too close or is easy prey that is starting to make an escape, use it on them.

Remember that it has a fairly low cooldown, so don't be afraid to use it, just use it at the right moments.

Laning Phase:

You can use your ultimate to swap enemies who are too close to your turret. This will put them into it, and force them to run.
If you do this make sure that where you swap to yourself isn't to close to the enemies team mate. If you are in mid then this shouldn't be a worry, just swap them when they are too close.

Tricks:
Sometimes you may be able to hide in the jungle behind a wall and swap someone into your team hiding as well. The swap works behind terrain, this may be helpful knowledge at some point so remember this.

This is my first build and guide, i would appreciate constructive criticism.
Please rate and comment. Thanks. :)