There really is no 'carved in stone' answer as of yet.  Typically I do most of my 'adjusting' on the Lux side of things.

Typical for me is 2400x3000 (much smaller for tests 600x750 typically), microdisplacement on, I tend to turn off subdivision as it almost always mucks with my scene.  Reduce Fireflies set to 2-3.  Lights I assign individually so I can adjust them on a case by case basis, same with emitters.  Wattage 50-200 (depending on how bright I want them), Gain 1-5 depending on need in the scene.  I turn on scaling as I almost always miss adjusting the diffuse/specular on something in my scene.

It really isn't like Poser at all, you can't say settings of X will give you a nice crisp image quickly.  I wish there was a magic formula.

Maybe others have a more 'precise' set up they use, but I am a person who has to fiddle and play with buttons and dials just to see what I can get out of it.  Bright images will render much faster than dimly lit ones as well.

And no offense taken, we are all learning here, none of us have had Guru stamped on us yet.  Though Snarly, Laurie and Magnus are probably closer than the rest of us.