Guitar-chord.org is a guitar site with information about chords primarily.
A large numbers of chords are presented in many chord categories, including both common and uncommon chords.
The idea is to bring more than just diagrams of chords by also giving tips about how and when the chords can be used properly.
Thus, "Chords put in context" is the motto for this site.
Check out the Guitar-chord.org YouTube channel.