If you are talking about the xml documentation that you can add to a class library, then you will need to utilise 'sandcastle’ to do this with doc to help.
If you open up the main Doc to Help help file you will find a section entitled 'Documenting Your Class Library with Microsoft Sandcastle.’ This provides a pretty good walkthrough of exactly what you need to do.
Just for your information there is an excellent tool to help create reader friendly comments in code files called Atomineer. It’s well wort investigating if you do a lot of code commenting.
Dom