You have probably heard about Google Docs, and you may have used it. We use it for file sharing, and it has served us well. But, it can be annoying when someone need to download and use the files in a Microsoft Office application. A year ago Microsoft started offering online versions of Office applications, and now Microsoft is offering Office 365, which allows editing, storing, and sharing Office files online for free if you have a copy of Office applications on a local computer.
Early reviews are saying Google Docs and Office 365 are so dissimilar they should not be compared, but they both try to do the same thing--offer online access to files and give people the ability to use and share those files. If you like Google Docs, but are not entirely happy with it, then try Office 365.