In the App list, tap Office
On Places, tap Office 365, tap Set up.
On Add an Account, tap Outlook. Type your full Office 365 email address, and tap sign in.
Give your account a few minutes to set up. As Louis C. K. Says "Give it a minute, its going to space. Can you give it a second to get back from space?" :D
Email, calendar, contacts, and OneDrive for Business are set up automatically. Tap done.
On the Office 365 page, sign in with your Office 365 username and password.
Check Keep me signed in if you don’t want to sign in each time you open an Office 365 document.
Tap Sign in. Your OneDrive for Business and Team Site are now added to Places.
For a Quick Setup Guide, download the attached pdf from Microsoft