Add some default text to Ctrl-Alt-F1 console to remind myself how to reboot properly

In the text console, you'll see a line with a text like Ubuntu 10.04 darkstar tty1 just before the login prompt. This message comes from the file /etc/issue, which you can customize to your wishes. The escape sequences are described in the getty(1) manual page.

Edit the 'message of the day' (motd). This is shown whenever you log in to one of the Ctrl-Alt-Fx terminals. You can edit it with this command: sudo nano /etc/update-motd.d/10-help-text. This is a shell script that prints a help message to the screen. It is only part of the motd. The other 'fragments' can be found in the /etc/update-motd.d directory.