How detailed do wireframes need to be? If they are line drawings, do you include color or images? The more detailed you make your wireframes, the more likely you are to manage expectations. Colors and images are typically reserved for the comps (PSD images) of the site created during the theming process.
Comparing Levels of Detail
The illustrations below represent three levels of detail. Notice in the first wireframe, we get a feel for where components are located. The second lets you know the type of components. The last provides details about the components.
Thank you for your interest. I apologize for any inconvenience this limited access causes. This online guide is now a book called Drupal: The Guide to Planning and Building Websites. The content of the guide is being updated, expanded, and edited. It will include tips for D6 and D7. I hope you will find it useful.