Oracle By Example (OBE) has a series on the Oracle Database 2 Day DBA guide. This OBE steps you through the tasks in this chapter, and includes annotated screenshots.
To view the Managing the Oracle Instance OBE, enter the following URL in your web browser:
https://apex.oracle.com/pls/apex/f?p=44785:24:0::NO:24:P24_CONTENT_ID,P24_PREV_PAGE:6285,1