The following article in the Office 365 community, Plan for and deploy Active Directory Federation Services 2.0 for use with single sign-on, provides some good, detailed information about configuring single sign-on so that users in your environment can use Office 365 features without using multiple passwords.
You can deploy a new AD FS 2.0 infrastructure to provide your Active Directory users, who are logged on to computers located physically on the corporate network or that are logged on remotely to the corporate network, with single sign-on access to Office 365 services using their corporate domain credentials.
Once you have deployed your AD FS 2.0 production environment on-premises, you will need to establish a relying party trust relationship between the AD FS 2.0 federation server farm and Office 365. This relying party trust acts as a secure channel where authentication tokens can safely pass between your organization and Office 365 in order to facilitate single sign-on access to Office 365.
It discusses ADFS 2.0 planning and deployment and includes multiple step-by-step procedures for configuring your environment.