[DM-MUG] Mac that won't 'start up'?

[Victoria L. Herring]

 From my sis ref her MacBookPro:   I closed out of my apps last night 
and "shut down" my Mac.  Went back and tried to turn it back on and 
nothing - no lights, action nor screen.  The little green light was 
on.  I pulled all cords from it and went to bed.  This morning I put 
the little power cord back in and it came back on and is doing well, 
but what would call the machine to just simply not come back on?  I 
looked in my MAC for Dummies book, but it doesn't address problems 
such as nothing nada zip;

any thoughts?
-- 
Victoria L. Herring, Travel Research/Photography, 
http://www.JourneyZing.com; Lawyer, Discrimination/Civil Rights, Des 
Moines, Iowa http://www.herringlaw.com; personal blog, 
http://victorialherring.typepad.com/serendipity/