Pretty broad question, but for installation issues with Oracle on Linux, I have found this site very helpful if used with the installation notes as well as some the documents available on Metalink.
Good Luck
http://www.puschitz.com/OracleOnLinux.shtml
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If you're not committed to RedHat, you may want to look at Oracle Linux. It's an Oracle enhanced version of RedHat. Check it out -- http://www.oracle.com/us/technologies/linux/overview/index.html