Which tools you use and why for automatic documentation / comments generation with Visual Studio
StyleCop is a great tool from Microsoft for checking that comments exist for all of your code elements. The tool performs static analysis of your code to ensure that your code conforms to specific built-in or custom defined rules.
GhostDoc for VS is a great tool. I use it with VS2005 and 2008. Works very well and best of all is free.
http://submain.com/products/ghostdoc.aspx
You can comment class members with a simple right-click context menu, amongst other things.
something with a solid preview and maybe even a WYSIWYG editor, some help if you want to embed an image or sample source code!
This is exactly where VSdocman can help you.
I've written a free addin, AtomineerUtils - this is like GhostDoc, but much more powerful (gives better auto documentation, documents thrown exceptions automatically, word wraps the comments to keep them tidy, etc).