This video explains how to add one or multiple users at a time in the Office 365 admin center. Get the instructions at https://support.office.com/en-us/article/Add-users-to-Office-365-for-business-435ccec3-09dd-4587-9ebd-2f3cad6bc2bc
Users on your team each need a work or school account before they can sign in and use access Office 365 for business. Microsoft Office 365 delivers the power of cloud productivity to businesses of all sizes, helping save time, money, and free up valued resources. Office 365 combines the familiar Microsoft Office desktop suite with cloud-based versions of Microsoft’s next-generation communications and collaboration services—including Microsoft Exchange Online, Microsoft SharePoint Online, Office Online, and Microsoft Skype for Business Online—to help users be productive from virtually anywhere through the Internet.
Learn more about Office 365 at http://products.office.com/en-us/business/compare-office-365-for-business-plans/?=SOC_YT_SMBOpt_OfficeSku_addusers