Pingo has a collection of realistic HDR Studio Lights with some free samples available for download. These would be ideal for connecting to the color attribute of an Arnold light such as Quad or Disk to give realistic color and reflections.
An introduction with some basic concepts and explanations around OCIO config and synColor config files has been added to the MtoA (2017) user guide in the links below.
“When rendering skin, you would use a Radius color value like R:1.0, G:0.35, B:0.2, indicating that red should scatter deepest and green and blue less. This would replace the three layer workflow for skin where you would make the deep layer red to indicate that deep should scatter with a larger radius. Setting scatter_radius.R to a larger value would correspond to that.”
Below is a an example of such a skin shading setup (digital Emily files can be downloaded here).
Arvid Schneider has created a video that goes through the skin shading process:
Some fantastic examples of Bifrost, rendered with Arnold for Maya:
Truca Team have an Arnold shader suite with over 256 shaders available for C4DtoA (using Arnold 5).
There are now two versions of the Arnold User Guides. For example:
If you are not sure which version you are on, have a look at the top and it should say which version, for example: arnold for maya user guide 5
Also, the url for Arnold 5 has an A5 prefix, like so: