You should know how to use the mksysb command to create a backup image of the system and how to restore from it.
You can use the AIX System Management Interface Tool (SMIT) utilities to install software and configure devices. If you haven't used SMIT before, look through the SMIT overview in the System User’s Guide; Operating System and Devices manual. In this information the instructions tell you to start SMIT using the smitty command, but you can instead use the smit command if you prefer a Motif-based interface.
You need some understanding of how AIX handles device definitions, how it structures file systems and directories, and how it uses processes and page space. All this information is available in System User’s Guide; Operating System and Devices.
You also need to know how to use a text editor to edit files.