If you need to develop a server side Adapter in VB.NET, you can find a tutorial at
http://www.lightstreamer.com/r/hello-dotnet-cometdaily
If you need to develop a VB.NET Client, you can find the full source code of a demo application that show real-time prices under "Lightstreamer\DOCS-SDKs\sdk_client_dotnet\examples\DotNetClientStockListDemo".