Context-Sensitive help With c# 2010

Hi All,
I am currently doing a project and I have to have context-sensitive help for at least 2 functions of the system. Anyone knows software I can use for this? Something that will look professional because this project is quite a big deal. I am using Visual Studio 2010 and my project is a WPF desktop app.

Thank you,
NB: I tried using sandcastle but it gave me some errors