First, I would check in /usr/bin to make sure the mySQL files are present. Just cd to /usr/bin and do ls *mysql* You should get quite a few entries.
Before you can start using mySQL, you need to make sure the daemon is running (mysqld). This is best started with the safe_mysqld program in /usr/bin. A common way to kick this process off from the command line is:
Once the daemon is running, you can use mysql to access/create/modify databases.
Read up on it bit here:
You can probably start with chapter 2 "MySQL Installation". Figure out where in the process you are after installing the rpm and do the setup and tests.