Click here for a file named ".cshrc_oracle". Open it up and add the lines in it to a file called ".cshrc", which is located in your home directory. (It would be a good idea to copy your current .cshrc to another file in case it does not work out after modifying it.)
You need to add the following line at the end of the file .login, in addition to the change (above) in the file .cshrc
set path = ($ORACLE_HOME/bin $ORACLE_HOME $path)
An example