Office 365 is the new edition from Microsoft under the Office online series. Few minutes before I have sign up to the Office 365 Enterprise Preview. I can see the lot of services available as follows,
- Exchange Online
- Identity Service
- Lync Online
- Office 365 Portal
- Office Subscription
- SharePoint Online
To SignUp Office 365, Click 
The following link describes the process to signup the Office 365 Preview, Sign Up for an Office 365 devloper Site
After signup the page will redirect to the Office 365 Admin Preview Center.
From Admin menu in Top-Right corner, we have the links for SharePoint, Exchange and Lync Admin Pages.
Navigate to each menu and play with the options available on each server Admin Pages.