Organic Groups is one of those modules that have had major changes beween Drupal 6 and Drupal 7. While the D6 version (due to legacy) had its own solutions for lists, group audience and other things, the new version utilizes entities and fields to its fullest – and relies on Views for creating lists of just about any type.
The benefits of not creating its own solutions for associating data with entities and creating lists is greatly increased flexibility. The Drupal 7 version will not – like the D6 version – have sub modules like Organic Groups Flick block, Organic group profiles or other modules that provide functionality that you normally expect to get by combining OG with your Drupal framework module of choice.
The cost of relying on other modules, though, is increased complexity. Organic Groups comes with a nice example feature that sets up the most common configuration in a snap, but to really make use of the module you need to know how to use relationships and contextual filters in Views, how to use relationships and Views content panes in Page manager, and how access and utilize data in Rules.
The screencast series Learn Organic groups tries to explain how to use OG and make the most out of it, by using it together with other important Drupal modules. I hope it will be useful for you.
PS: Also check out Amitaibu's suggestion to rewrite the references for Organic groups, and the excellent screencasts about OG over at ModulesUnraveled!
Photo credit to krayker at rgbstock.com