How to theme notification links on the pages inside organic groups (like group.drupal.org pages)
Details about nice "subscription" interface below each post on groups.drupal.org.
Organic Groups and themes
Theming layout of OG front page
http://drupal.org/node/90149
Default theme for an organic group ( a simple workaround)
http://drupal.org/node/215914
Specific theme for one Group (snippet for a custom module)
http://drupal.org/node/272121
Default theme for a group (Issue for Organic group)
http://drupal.org/node/202442
Theming Organic Groups home page with Views, CCK and OG - problems with node-og.tpl.php and Views settings
http://drupal.org/node/116332
User interface for preferences to vary by content type or by group
http://drupal.org/node/192933
Guide maintainers
