The Yahoo! Design Pat­terns Library is what you could call a series of best prac­tices for web inter­ac­tion design­ers. Of par­tic­u­lar note are the ‘Rep­u­ta­tion’ Solu­tion Pat­terns:

A per­son par­tic­i­pat­ing in a social struc­ture expects to develop a rep­u­ta­tion and hopes for insight into the rep­u­ta­tions of oth­ers, but each designed model of par­tic­i­pa­tion and rep­u­ta­tion embod­ies its own set of biases and incen­tive struc­tures. Bal­anc­ing these forces deter­mines in large mea­sure the suc­cess or fail­ure of a social system.

All released under a Cre­ative Com­mons attri­bu­tion license.