Layout idea: proof of concept
I wanted to see if I could do overlapping boxes, to try to break up the "griddiness" of MediaWiki pages. This has rounded corners in Firefox, adding curviness as well.
Obviously much more could be done to improve this with better fonts, colors/gradients, images/icons, and so on, and the CSS would need to be refined and transfered properly to a stylesheet.
This is intended to be the "first help page", linked from the sidebar and providing an entry into more sophisticated help. See Overhaul of Help pages for discussion.