A few places.
Check out the MSDN Library. Along with the API, it has a lot of good references and tutorials.
If you can't find what you need by doing a Google search, you can always just ask here, or on the MSDN or CodeProject forums:
Ok. I just went to the MSDN and looked up DataTable and it gave me this:
Dim workTable as DataTable = New DataTable("Customers")
And says the new DataTable is now called Customers. So what does that make workTable? Why can't I just say:
Dim Customers as DataTable.