If you are so inclined, you can read the following documentation in the order listed. On the other hand, you can just follow the steps in this document.
Some release notes are available pre-installation and others are only available after installation. Before installation, some of the release notes can be found in the \doc\readmes directory of the first component CD-ROM. After installation the readme files can be found in
Product subdirectories under ORACLE_BASE\ORACLE_HOME directory.
Files in the ORACLE_BASE\ORACLE_HOME\relnotes directory.
Below is a list of the most critical release notes:
Oracle9i Database README Release 2 (9.2)
Oracle9i Net Services README Release 2 (9.2)
Oracle JDBC Drivers release 9.2.0 Readme