Light types are fairly similar across the renderers that I've experienced and the ideas like three point lighting, IBL, trace depths, color temp, exposure, decay, indirect illumination bounces, samples, common surface shader properties (diffuse color, weight, roughness, reflectivity, gloss, bump, refractions, transparency, self illumination etc), shot composition, color management, alpha masks, file types and bit depth are quite general as well. Then its just a matter of learning the different labels and possible quirks of a given renderer which a quick help doc/google search would likely clear up.

When I tried Arnold, I was like "Wait, that's it? No need to plug this into that and the fiddle with the other thing?". If anything mental ray has forced me to learn a lot which might be a good/bad thing depending how you look at it.