How can I invite members to my organization?

From the home page of your Admin page click on on Add Members from the top right.

Type the email address of the person you'd like to add. You can add up to 100 members at once by separating each email address with a comma. There is no technical limit to the number of members you can add to each department though each additional seat has a price associated with it.

Click Invite, then OK.

You will see that they have a pending invitation. The person will receive an email prompting them to join your team and once they do their status will change to Activated.