I'll walk you through how to get a wysiwyg editor up and running on your drupal site in a few simple steps. I'll cover the basics like how to get Bold and Italic buttons, and also more complicated things like in-line image placement. I also have few words for you on best practices around input filters and role-based usage.

My favorite combination of modules for setting up a WYSIWYG editor are:
WYSIWYG API (http://drupal.org/project/wysiwyg)
IMCE (http://drupal.org/project/IMCE)
IMCE WYSIWYG API bridge (http://drupal.org/project/imce_wysiwyg)
Better Formats (http://drupal.org/project/better_formats)

Step By Step Instructions available here:
http://www.jenlampton.com/presentations/WYSIWYG.pdf