Microsoft is working hard to get users to upgrade their systems to the new Office 2013 suite which was launched exactly one week ago. Though the UI hasn't changed too much from the previous version there are definitely some improvements and some differences that users will need to understand and learn to navigate through.
To help you, Microsoft has just launched their Office 2013 Quick Start Guides. These can be accessed here. They are broken down by each application (Word Guide, Excel Guide, etc) and users can either print the guides or simply store them as a .pdf file. The guide breaks down each of the apps and explains what all the buttons and options do as well as show a user the true capabilities of such an application.
For some of you these may come in very handy especially if you are switching from a really old version of Office and you get overwhelmed by all the new changes. But even if you a more experienced user you may still learn a trick or two to make your work day go a lot smoother.
Source: Microsoft Quick Guides