With the release of the new Office, there are lots of new resources for you to look at. To get started, have a look at the below links:

1. Office for IT Pros
2. FAQ
3. Product Guide 
4. Try with Office 365 (works with existing Office using Click-To-Run technology)
5. Try without O365 (requires uninstallation of previous Office)

Other Office 2013 Programs :

1. Lync 2013
2. Exchange 2013
3. Project 2013
4. SharePoint 2013