Where to stain and poly

I have just completed a writing desk with drawers. The top and main frame are separate at this time and the top will finished differently.  I have brushed on one coat of shellac as a wash coat and am ready to stain. Do I stain the entire frame, inside and out?  What about the runners and kickers where the drawer slides? I have been told no poly on the drawers so I've already finished them already with a rubbed out shellac finish. I'm planning on topcoating the outside with a wipe on poly. Do I do the interior spaces of the frame with poly?  Does anyone have any links where I can see sample or read about where to stop and start the stain and topcoat?
   Thanks