Begin with a white-primed model, then give a thin coat of Badab Black to the entire model.
A layer of Mordian Blue was applied to the left half of the model (or the right half from the model's perspective) - you may need to apply multiple coats of Mordian Blue to get a nice smooth coat.
A layer of Enchanted Blue was applied, leaving some of the Mordian Blue visible in the recesses. If Enchanted Blue is hard to find in your area, you can use Magic Blue from Vallejo's Game Color line.
Enchanted Blue was mixed 50/50 with Skull White and used to give an edge highlight to the model using a fine detail brush.
All of the blue areas on the model were given a wash of Asurmen Blue to deepen the blues and tie them all together. Your blue is now finished.
Iyanden Darksun was applied to the chest eagle. Charadon Granite was applied to the joints, cables, and vents. Blood Red was applied to the eyes and purity seal. Dheneb Stone was applied to the parchments.
Devlan Mud was washed over the parchments. Iyanden Darksun was mixed 50/50 with Skull White and applied to the edges of the eagles wings and heads. Fortress Gray was used to edge highlight all of the gray areas.
Bleached Bone was applied to the parchments, leaving the previous colors visible in the recesses. Badab Black was used to wash the gray areas, tying the colors together.
Skull White was used to edge highlight the white areas of the armor.
I went back at this point and smoothed out a lot of the white areas with Fortress Gray, to get rid of the harsh difference between the white and the previous black wash. Skull White was then reapplied to the edges of the armor. Now you are finished. Just finish the base, and add a bolter and get him on the table!