There is no "quickie guide" for this.
An actual understanding of both C# and MS Office is required.
Add to that practice and understanding of the Microsoft.Office namespaces.
Open any WIndows Forms project in Visual studio.
Right-click on the project and choose "Add reference..."
In the next dialog choose the ".NET" tab.
Scroll down to "Microsoft.Office" section and notice there is..
- Microsoft.Office.InfoPath
- Microsoft.Office.Interop
- Microsoft.Office.Tool
s
Each of those have sub areas.
This will actually require learning and practice on small projects before starting anything that might be considered ready for an employer.