Okay not strictly an InDesign question, but here goes anyway:
I'm about to set up a 4-panel brochure on legal-sized paper. Haven't done one of these in ages. Years ago, I used to just divide the page into 4 equal parts. Now I know better as the inner panels need to be a little narrower so that the fold is correct. Question is: How much narrower? Or to be more direct: What should the width of each of the 4 panels be?