Your custom welcome message
When you enter on any virtual console (ctrl+alt+F1..F6) or a shell in a graphical environment, you will see the next funy message, before you loged in:
Have a lot of fun!
You realy can change this for a serious thing, like an information, for example, about the administrator and site to be a little more serious.
General message
I assumed that you are loged in like any valid user in your system.
First type at the prompt the su - command and give the administrator password.
You notice the change of the end character of the promtp from ">" to "#", that's indicate the superuser mode (administrator) is in effect.
Second type vi /etc/motd to edit the content of the motd file on the etc directory. You will see in the first row the "Have a lot of fun!..." message and for the rest of rows a character named "tilde".
Third time to rewritting, to delete this press two times when the cursor is in the first row, the "D" key of the keyborad, this means delete a row then press the key "i" (insert) to enter new text, I always write a line with the "_" character of 20 wide and then press "enter". On the next row you can type the name of your place of work and press "enter" again, on the next row type your name and pres "enter". In the next row write your department and then press "enter", for the last row write the character "-" about 20 times to match the first ones and do not forget press "enter" for the las time.
The last step is write to the file: press the "esc" key to finish the edit and then press ":", you notice at the bottom of the window or screen a line with the character ":" and the cursor, now you can type wq this indicate to the vi editor the next is write and quit to finish and return to the prompt.
The next time you enter on a shell you will see your message.
Have a lot of fun!
More fun on login
When you login, you can have random quotes displayed for you. Each user can change the file .profile. Remember there is a dot (.) in front of .profile. At the end you see something that looks like:
#if [ -x /usr/bin/fortune ] ; then # echo # /usr/bin/fortune # echo #fi
Just remove the # on the last lines and install the program fortune with YAST and each time you open a terminal, you will see a nice quote or wisdom.