Orcs are ridiculously powerful. I have been play testing several deck builds using 2x Core and 3x Skavenblight. It seems as if Orc Rushes cannot be stopped unless you draw a God Hand. The problem with this is that every Orc Hand is a good hand, whereas Dwarf, Empire, and Chaos hands can be hit or miss (in terms of speed). Most of the time, I've managed to be able to burn a zone within 3 turns with Orcs and continue pushing offense for a win by turn 5. Orc synergy with itself is just way too good. Not to mention...there are tons of possible "God Hands" with Orcs.
As request here is my decklist.
Orc Units
3x Spider Riders
3x Lobber Crew
3x Squig Herders
3x Clan Rats
3x Crooked Teef Goblins
3x Followers of Mork
2x Ironclaw's Horde
2x Urguck
2x Grimgor Ironhide
Orc Tactics/Support
3x We'z Bigga!
3x Favour of Mork
3x Choppa
2x Rip Dere 'Eads Off!
2x Totem of Gork
2x Grimgor's Camp
2x Troll Vomit
2x Waaagh!
2x Smash `Em All!
1x Pillage
1x Smash-Go-Boom!
Neutral Cards
3x Clan Rats
2x Warp Lightning Cannon
1x Greyseer Thanquol
How to Use the Deck
You will be playing most of your cards directly into the Battlezone. You will pretty much ignore the Kingdom Zone, instead opting for Quest Zone.
The only Orc cards that go to Kingdom Zone are: Lobber Crew, Grimgor's Camp, and possibly a Development
For the Quest Zone, all your Squig Herders will go there, and possibly Follower's of Mork and a Development.
Using the Skaven
Clan Rats will be played into Kingdom or Quest Zones, one in each preferably. When your Kingdom Phase is about to end, corrupt a Clan Rat to give a Clan Rat in the Quest zone a power boost and thus drawing an extra card. Greyseer Thanquol can be played into Kingdom or Quest, once again, Quest taking preference.
Using Rip Dere 'Eads Off
You use this amazing card to bring in an Ironclaw Horde for that quick one turn push or to get into play Grimgor Ironhide for a turn. If you play Grimgor as a Development in your Quest or Kingdom Zone, when he gets revealed, he destroys the the supports and developments on both sides in that zone. You can also set Grimgor into your Quest Zone as a Development, then at the end of your Kingdom Phase, use Rip Dere 'Eads Off to both destroy enemy Quest Zone and draw extra cards (revealing him in your QZ won't hurt you since you have no supports there, only units). Why no Bloodthirsters? Because it's too situational. You need both Bloodthirst and Rip Dere 'Eads off. I'd never be able to pay for a Bloodthirster with normal resources, but I could afford a Grimgor or a Ironclaw.
Card Draw and Resources
As stated before, Lobber Crews and Grimgor's Camp go to the Kingdom zone, with the low cost curve of this deck, you never need that much. Lobber Crews are great since you can sacrifice them to force the enemy to lose a unit. Great way to put pressure on. You don't really need the resources, and it hurts them more than it hurts you.
Don't forget Urguck. You can play two We'z Bigger on him to put him into play for 1 resource and 3 loyalty. Which is just 3 total if you have no cards out. Then use his damage as more resources to bring in two 1 cost weenies or equip Urguck with Choppas. Also, don't forget the infinite Followers of Mork/Urguck combo. Urguck in play, Play Followers of Mork, damage Urguck for 2. Spend 2 damage to bring in another Followers, damage again, then spend 2 more damage to bring in whatever you want...
As far as the card draw. We'z Bigger on Squig Herders or Followers of Mork damaging Squig Herders or themselves will allow your Squig Herders to rake in 2 additional cards per Quest Phase. Cards are your friend, bigger hand means better odds of multiple turn rushes.
Offensive Combos
Waaagh!, Totem of Gork, Choppas. With three units in your Battlefield, you can do excess of 10 damage easily. Don't forget Greyseer can attack from anywhere.
Your Warp Lightning Cannons are great for preparing for an attack. Just make sure to put it on a unit with 2 health to prevent easy 1 damage pings (Urguck, Followers of Mork, Grimgor, or Ironclaw's Horde)
Your Warp Lightning Cannons are also great for CORRUPTING the enemy. That Dwarven beefcake with toughness in your way? Corrupt and burn. Counterstrike annoying you? Corrupt and burn.
Destruction
Troll Vomit: You'll rarely use this. It's a back up incase your rush has stalled.
Smash 'Em All!: Quest? Really? Yea. It's just incase your rush has stalled and also a great way to attract the enemy into attacking your Quest Zone.
Smash-Go-Boom: Late game development destruction. You should never need to play this, if you do, it means your rush failed.
Pillage: A great card, only one copy in the deck, it helps sometimes, don't need 3 copies.
Grimgor: He's your Ultimate Destroyer. Use him wisely.
Offense and Defense
Defense? No. Never defend. Let enemies through every time. Only time you'll defend is using Urguck vs a weenie. Even then, I'd advise against it due to Tactics cards. Dark Elf hero will be no problem, impossible to get it out early enough to hurt you. Burning? Highly doubtful they can deal more damage than you. Scout? This is probably the only thing that will hurt you. But if you are playing your Quest Zone properly, it should be no problem.
Attack every turn if possible. Concentrate on undefended zones for damage distribution. The one turn swing in to full burn is what you aim to do. If given the choice between burning an undefended zone with counters already on it and going into a defended zone with no counters, choose the zone with no counters. When the enemy has damage everywhere, they won't know where to defend. If you can early burn, I'd advise against it (unless it is a 0 damage to 8 instaburn), forcing the enemy to spread out is worth while.