Msdn help for Microsoft.Office.Interop.Outlook members

[DavidE]

Hi,
I develop outlook add ins whith vs 2005.
I try to find help for Microsoft.Office.Interop.Outlook members but I don't
have it on my local help(it's not exist in the index) but I can see
Microsoft.Office.Interop.Excel and Microsoft.Office.Interop.Word in the index.
Why I don't have it ?
I searched over the web but I didn't find any help for this namespace
members (classes ,interfaces etc. for example : Explorer interface ,
ExplorerClass).

How can I install it on my local machine and where can I find it over the web.

Thanks,

David