“Back to school” doesn’t necessarily mean lunchboxes and pencil cases, recess and rest time. Even those of us who’ve long put our school days behind us, whose framed diplomas now gather dust on our office walls, can sharpen our pencils (or pack up our paintbrushes or lace up our tap shoes or dig out our gardening spades) and get schooled. You’ve just gotta know where to go to make the grade.