This article deals with writing a 3rd party component, giving some basic information about the new Revolution ideas of components, packages and models. It also shows how to use a custom table with a custom schema in the new Revolution environment.
http://svn.modxcms.com/docs/display/~splittingred/2008/06/26/Writing+a+3rd+Party+Component+in+MODx+Revolution%2C+Pt.+I
P.S. If you have suggestions, improvements or alterations you’d like to make to these articles, please respond in the appropriate thread. They are very welcome.