Windows PowerShell has proven to be the go-to when it comes to efficient administration of SharePoint platform. Currently Microsoft is providing a sub-set of the on-premise shell to support the administration of its SharePoint Online counterpart; mainly SharePoint Online 2013. Microsoft has all of the up to date documentation released here: http://technet.microsoft.com/en-us/library/fp161362.aspx
Notes from the field, do's and don'ts, highs and lows.... you get the Point!