1)Right click on your desktop,
2)Click New
3)Click Shortcut
4)In type the location of the item, copy & paste following
"%ProgramFiles%\Microsoft Office\Office12\Outlook.exe" /nopreview
where Office12 in above is the version of Office. It may be Office11 etc so change it accordingly
5)Click Next
6)Click Finish

Now double click the above created shortcut to open outlook. You are done with turning off reading pane