On and Off
The very first thing you will probably need to do is to turn your computer on. The on switch is at the middle right of the front of your NUC. Press it for a second and then release. Don't hold it down for longer than a second. On screen you'll see NUC and some BIOS key shortcuts. This lets you know that your computer has started as it should. Then you'll see the Linux message, and a lot of code will flash before your eyes. You don't need to do anything until you arrive at the login screen.
Login
Choose your Session, enter your password, click either "Login" or your keyboard's enter key, and wait until your session appears. You are logged in and ready to go.
Shutting Down
From LXQt
There are various ways to shutdown your computer. If you choose an LXQt session, left click on the icon at the lower left of the screen and choose Leave --> Shutdown. Optionally, type 'shutdown -h now' in the Terminal without the apostrophes and then press the enter key on your keyboard.
From Openbox
From Openbox, you can right click anywhere on the screen where there is no window, choose "Leave" and then "Shutdown" from the dialog box. You can left click on the shutdown button in the panel at the left of the screen but beware this will shutdown the computer without asking for any confirmation from you. This option is for when you absolutely know you want to shutdown. You can also type 'shutdown -h now' in the Terminal without the apostrophes and then press the enter key on your keyboard.
If you don't want to shutdown your computer but want to secure your session, you can choose "Lock" from the menu when you right click on the desktop. Your screen will lock in a few seconds. When you are ready to return simply type your password. The "Exit" option is not really recommended from Openbox session.
Never shutdown the computer by pressing down on the Power button. Holding the power button down for a few seconds will shutdown the computer but should only be used when the computer is completely unresponsive and can't be shutdown by any other means.
Bugs
The NUC8i5BEH
The NUC8i5BEH model has a bug where very occasionally it will restart even if you chose shutdown. If so, instead of going blank the screen returns to the login. When this happens, just choose "Shutdown" from the menu at the top right of the screen. The computer will then shutdown properly.