Office 365 is Microsoft’s collaboration & office tool cloud offering. Having been available from 2011, the service has established itself as one of the world’s leading cloud services – no matter how you measure it.
These blog posts handle different configuration and customization cases I’ve encountered in regards to Office 365. Huge part of these are actually related to SharePoint Online, too. Which is kind of natural – SharePoint Online sites form a huge (if not the most visible) part of Microsoft’s Office 365 offering!