Pricing for Office 365 is tiered. Small businesses with up to 25 users pay $6 per user per month, which doesn't include Microsoft Office. (The suite works with already-installed versions of Office.) For larger enterprise customers, there's a wide range of pricing. For example, existing BPOS customers pay $10 per user per month (the same price they pay today), while enterprises that want a subscription-based version of Microsoft Office Professional Plus for their users, in addition to the rest of the suite, pay $24 per user per month.

When you first log in (Office 365 supports Internet Explorer and Firefox, but not Chrome), you're greeted by a simple, straightforward page that lets you navigate to the Web-based version of Outlook for reading e-mail, head to SharePoint to use its services, install or use the Lync communications server, install connector software that links your local Outlook client to Office 365, or install Microsoft Office Professional if it's not already installed.

The heart of the suite, and the feature that can provide the greatest benefit for small and midsize businesses, is Exchange hosted in the cloud. This offers the benefits of Exchange without the headaches of hosting.