If you want to do this temporarily, you can press the CTL-ALT-F1 keys. A different function key from F1-F6 will get you to a different virtual terminal. You can select this as the mode you boot up through YaST. Or you can edit the /etc/inittab file and change the lines:
# The default runlevel is defined here
Changing the 5 to a 3 will do it. Then run as root "SuSEconfig" so YaST picks up the change. (Not certain if this last step is necessary, but it is a good habit after making a manual configuration change.
SuSE does come with an on-line Administration manual.