This is the technical description of how to set up a group.  There is more to it than this please review this getting a group started post. (coming soon.)

To create a group, be sure you are logged in.

1. Go to the Groups page.
2. Click "Start New Group".   After clicking “Start New Group” you’ll get to the edit group screen. You’ll be able to come back to this screen and edit the group later if there’s something you want to change.
• Group title: pick a name for your group and enter it here.
• Group URL: create an address for your group. Your group name can not have spaces or numbers. You can use the underscore '_'.
• Image/logo: upload a photo for your group. Upload a picture from your compute to represent your group.
• Description: Write a description for people to see and be able to quickly  understand what your group is about.
• Default member role: This sets the default role for when members sign up. You can either enable them to post by default or prevent them from posting to the group at the outset.
• Create group: Your done with setting up the group and you’re ready to create it.

Please see also the following posts:

New group features a description of various features of ActiveRain Groups By Matt Heaton 

Groups 101 - Our First Definitive Guide on Groups. By Jason Price 

On Being A Groupie! -  Groups are a good thing.  By Rich Jacobson 

Group Types A description of some of the inner workings of groups.

Groups An introduction to groups.