Themegrill's Radiate theme offers nice usability, even for relatively inexperienced WordPressers like myself.
The design is exquisite, and it's easily customizable.
As a geezer, I especially appreciate the generous (readable) font size chosen for the theme.
Big shoutout for providing a nice documentation page: http://themegrill.com/theme-instruction/radiate/
And additional kudos for a very well-managed forum.