Your 'Group Profile' is displayed at the top of your group's homepage. You can edit this by clicking the 'About this group' option in the 'Settings' tab.
On the 'About this group' page, you can change your group's name and description, upload an image for your group logo (which can be displayed in your group's header and/or sidebar), or edit your group's contact details.
If you have your own external website, you can link to that from your 'About this Group' section as well.
Uploading a banner header
Upload a logo
Themes: Choosing the look and color of your group
Layout: Choosing content for your homepage
>>Customizing your group public profile
Customizing email templates