In Microsoft’s own words, an Office 365 group is the evolution of a distribution list. A group includes a shared workspace for email, conversations, files, and calendar events so group members can communicate, collaborate, and quickly get stuff done.
To create a group, sign into the Office 365 Webmail client (Outlook online). Click on "People" (where your contacts are). In the left navigation pane, look for "Groups" and click the plus (+) sign.
You'll see two types of Groups that can be created, but at the time of writing, there was no actual difference between the two beyond the fact that one is a public group by default (the Standard Group) and the other is a private group by default (the Professional Learning Community). However, you can set the privacy for either type of group in the first setup steps, so you can have a private Standard Group or a public Professional Learning Community. So at the moment, it doesn't matter which type you choose.
CHOOSE A NAME: Give your group a name.
GROUP ID: As long as the name isn't already being used by another group, then it can also be used as the ID. Microsoft will tell you if it's available or not.
ADD A DESCRIPTION: Add a detailed description of the group to help others understand its purpose. This description will be included in the welcome email when others join the group.
PRIVACY: To create a group in which anyone within your organization can view its content and become a member, select Public. To create a group in which membership requires approval by a group owner and only members can view group content, select Private.
SUBSCRIBE BOX: To enable subscribed members to receive email and calendar event notifications in both their group inbox and personal inbox, select Subscribe New Members so they receive group conversations in their inbox.
Now click the "CREATE" icon up at the top.
If you're ready to add members to your newly-created group, continue with the create group wizard. Otherwise, select Not now. You can always come back and add group members later. To add members, type a name or email alias. As you type, suggestions will be displayed. Select the appropriate person or click Search Directory. To add multiple members, start typing the next name after each selection. You can add someone with an external email address (i.e. an individual outside NSCAD with their own company email address, Gmail account, etc.) by typing their full email address in the field. They will be considered a "Guest". All the guest member's interactions occur through their email inbox. They can't access the group site but they can receive calendar invitations, participate in email conversations, and open shared files using a link or attachment.
When you have finished adding members, click on the Save icon at the top.
When you open your new group, you'll see tabs for Conversations, Files, the Group Calendar and other resources for collaboration. Under the Files tab, you'll see any files that have already been uploaded, or even attachments that were included in conversations, but you can't actually upload files here. To upload files, click on "Browse Library" and you will be redirected to the Group's SharePoint library where you can upload or simply drag and drop files. Back in the Files tab, you'll also see a "New" button, which is for creating a new Word, Excel or PowerPoint file using the online versions of those Office programs.