I've just added Yafray to my bag of tricks, and rendered a couple of images.  Based on what I'm seeing, there's a LOT I don't know about Yafray!  I uploaded an image to the Blender gallery here on Renderosity yesterday of a room with a table lamp.  The image I posted was rendered in Blender internal.  When I rendered it in Yafray, this is what I got.  It's the exact same file - the only thing I changed was the Blender internal / Yafray button.

Aside from the obvious lighting differences, which are quite a bit more radical than I had expected, there is now an empty picture frame on the wall.  What happened to the image?  It's just a jpg, like all the other textures in the image.

Should I be using different lights?  Different settings?  Where do I start?

Please keep in mind that I'm an accountant, not a techie, and I'll be quite grateful if you'll start slow and use short words!

Attached Link: http://www.blendernation.com/2006/08/23/yafray-lighting-discussion/

You might want to take a look at this web page - blendernation has lots of good info.

I would add some fill lights (area lights at low intesity) in the room.  

Also on the render tab a couple of extra tabs will appear for yafray, switch on yafray GI on the second tab (slows things down but GI = Global Illumination adds a whole host of useful lighting clculations.

I imagine that your picture had ray mirror enabled and now yafray sees the setting as too high and is reflecting too strongly, go back to the material and try unchecking the ray mirror button or lowering the reflectivity.

If that all sounds like gobbledygook, ask again and I'll try and help more effectively

scenes that are made for the blender internal can not be guarenteed to work in yafray, lighting has to be made specificaly for yafray in most cases, and materials have to be made specificaly.  the texture should work if it is the only texture on the material, but you need to make sure the normal is facing the correct direction.  on the glass window, make sure you have fresnell mirror turned all the way up.  if you want to light that scene with only the lamp, you need to turn on global gi in the yafray gi panel.  turn it up to full, and then low.  enable photons and cache and turn the refinement down all the way.  this should do the trick of lighting the whole scene with light reflected off of the walls.

Great!  I'll start there, and see how I do.   I understood everything you both said!   That was just the right setting on the "techie knob."   Thanks!