OpenOffice cannot open AppleWorks files. Other than AppleWorks itself the situation is this:
•Word Processing documents can be opened directly only in Pages (AppleWorks 6 only).
•Draw Documents can be opened directly only in EazyDraw (the more expensive version from their website, not the cheaper one from the Mac App Store, and you will need v4.0 'Retro' not the most recent version) or Intaglio (though this appears not to be able to handle very complex drawings).
•Spreadsheets can be opened directly only in Numbers.
•Presentations can be opened directly only in Keynote.
To use other programs, or open Painting or Database documents at all, you must export from AppleWorks first.