If you've not done any programming/development before, it'll be a steep learning curve 
You can start by grabbing Visual Studio Express from http://www.microsoft.com/express/ (I'd recommend starting with C#, but some prefer Visual Basic). Express is the cut-down version of the full (expensive) developer toolset from Microsoft, but it has just about everything you need.
Have a look at Brendan's site for some templates to start with: http://www.brendangrant.com/WHS/WHSDevTips.htm
Once you've figured out how to make a basic Tab appear in the WHS console, you'll want to read the WHS SDK to find out how to access WHS settings and data: http://msdn.microsoft.com/en-us/library/bb971779.aspx