Hi Hutch,
Either VB.NET or C# - You need to know at least one of them. If you are starting, then you should pick C# - DNN itself is now based on C# and a lot of training is also based on C#
One lightweight option for you could be RAZOR, which can get you up and running very quickly and does even require Visual Studio. We have some reazor tutorials around as well. You should give it a try.
Cheers,
Aderson