I used to paint uruk hai armour following the gw guideline long ago and its so easy and nice you gonna love it. (im using some Keyser uruk hai pics to better show the results of stages before the final uruk hai stuff I got around). If you need further check it out on articles, check Keyser article..
How to paint uruk hai.
this should be something you need :P
Undercoating.
Undercoat the model with Chaos Black paint or Citadel Colour Spray. If you are painting the model in chaos Black, make sure to thin the paint down with 25% water, so the paint does not obscure the details on the skin and armour.
Armour and Weapons
Paint all of the armour [Including Shield and Helmet and Sword] with a basecoat of 75% Tin Bitz and 25% Chaos Black. Let this dry, and apply a layer of Tin Bitz.
Once this is dry, drybrush the Weapon, Armour, Shield and Helmet with Chainmail.
To finish off the armour, apply a wash of Chaos Black, before applying a final highlight of Mithril Silver to the raised edges.
Flesh.
If any paint from the armour has dribbled onto the flesh, now would be a good time to paint Chaos black paint over the flesh areas.
To paint the flesh, apply a basecoat of Dark Flesh to the flesh areas. Make sure to leave some Chaos Black showing in the deepest recesses of the flesh. Then, apply a layer of Dwarf Flesh to the flesh areas. Leave this to dry. To finish the flesh, add a highlight of 50% Dwarf Flesh and 50% Dark flesh. You may also want to add a Black Ink wash to the flesh, to define the muscles more and a mix of dark flesh/scad red to highlight the muscles even further.
Leather
Paint the Loincloth and other leather areas, (Pauldron straps, Greave Straps, etc.) in Scorched brown. Leave some Chas Black showing in the deepest recesses to represent shadw. Apply a Black Ink wash if you accidentally paint over the Chaos Black.
Details
To finish off the model, use a fine detail brush to paint the teeth Rotting Flesh. Carefully pick these out, as the paint of the undercoat may have accidentally obscured the fine details.
You may want to lightly drybrsh over the mouth, to pick the teeth out easier. Make sure to be working in a well-lit place, to make sure you do not accidentally paint over the flesh.
You may also want to apply a White Hand onto the armour or helmet. To do this, simply paint a blob of Skull White paint onto te surface of the model using a standard brush, and sing a fine detail brush, paint 5 lines to represent fingers. Paint the base Cdex Grey, and your model is ready for Battle.
you get something like this after the horde is done
Hope this helps