I've created a video that shows you how to make use of existing applications in the Maemo 5 platform to learn how to read, speak and write Chinese with Nokia N900:

http://www.youtube.com/watch?v=CBICeIq2BIM

gTranslate, eSpeak GUI Client and Stroke Order Chinese Input Method mentioned in the video are available in the Maemo.org extras-devel repository. (Note: Software in the extras-devel repository are in development status, use them with extra care.)