DEX has a helpful 'Tip of the Day' dialog that you can view on demand or optionally have appear every time you startup DEX.

To display the 'tip of the day' dialog use the Home ribbom menu.

The dialog is shown below and contains handy tips on using DEX.

Show the next 'tip of the day'.

Show the previous 'tip of the day'.

Display this help topic.

Close the 'tip of the day' dialog.

If checked, then the 'tip of the day' will be displayed everytime DEX starts otherwise you will need to use the Home ribbon menu to manually show it.