First, skip VB.Net. It would seem to be the first choice as VB used to be simple to pick up and implement. However, you'll find most of the code examples in C#. That will be your preferred language when working with Revit. Plenty of examples to learn from and plenty of support. Converting code from C# to VB.Net isn't straightforward.
Second, download and install Visual Studio Express. VS 2013 does have some tweaks you'll need to get familiar with. Older versions were a little simpler to set up for Revit so you might want to see if you can install an older version.
Third, read everything at
http://adndevblog.typepad.com/aec/jeremy-tammik.html There is plenty of sample code and discussion there to get you started. You'll definitely want to download Jeremy's sample tools including Snoop DB from Github. It will help you learn the underlying structure of the Revit objects and API.