Your colleagues and friends can be invited to view your Channels and Guides, and to contribute to your Hub.
Within your Hub Settings, click on "Members".
A new window opens that shows you all the people with access to your channel. Click on "invitenew people" (top centre of the window)
Enter the email address(es) of the people you want to invite and click "Send". Your invitees will receive a mail from Guides, inviting them to your Channel / Hub.