2. Set Group Permissions
You will be presented with many permissions.
Some of these permissions, such as those in the Group category, related to managing the group itself.
After the Group category, you'll see a categorized list of permissions grouped by Group Node type - for example, one category is Page, another category is Webform, etc.
In the columns, you'll see the different roles that belong to the group.
Group Manager is responsible for all of the permissions in the Group category as well as all of them in the individual Group Node categories.
Group Contributor is only concerned with creating and editing content in the Group Node categories.
Member has content viewing privileges only . They may view content that is private to the group.
Outsider is someone who is a registered user of the overall site, but not a member of the specific group.
Anonymous is someone who is not a registered user of the site.
Keep in mind that roles and permissions are subjective - there's really no general "wrong" way to do this. It all depends on what your site needs to function as you want it to function.
Once all permissions have been checked, click the Save Permissions button.