The following collection of light reading is to guide those who need to connect SharePoint Online and existing on premise Exchange and Active Directory
The aim is to have on log in with cloud and on premise services synchronized.
This area is outside my skill set, but has already been raised with me twice, so this article is aimed at giving you some resources to read and pass on to your IT people.
Get your head in the cloud: Hybrid for SharePoint Server 2013/Office 365: http://blogs.technet.com/b/tothesharepoint/archive/2013/04/16/get-your-head-in-the-cloud-hybrid-for-sharepoint-2013-office.aspx
Questions about Single Sign On (SSO) with Office 365 for Education
How to set up Hybrid SharePoint
Configure single sign-on: http://technet.microsoft.com/en-us/library/hh967628.aspx#BKMK_2
How Single Sign-On Works in Office 365
Prepare for Single Sign on:
Plan for and deploy Active Directory Federation Services 2.0 for use with single sign-on
Single sign-on: Roadmap
Deploying and Configuring ADFS 2.0
Video Screencast: Complete setup details for federated identity access from on-premise AD to Office 365