Having an account automatically log in at boot is a HUGE time saver, and absolutely essential when your computer doesn’t have a keyboard attached! In Ubuntu, this is easily done through the System Preferences menu.
First, click the gear icon in the upper-right corner and select “System Settings…”
Then, in the lower-right, select “User Accounts”
Highlight the account you would like to automatically log into and click the “Unlock” button in the top right corner.
Click the “Automatic Login” switch, so that it says “ON”
Click the “Lock” button, close the window, and you’re finished!
NOTE: Some derivatives of Ubuntu do not have this feature, but the functionality can be added. Choose your derivative from the list for instructions: