I know several interesting works, but I should warn you: they are all in C#.
You can still write in VB.NET, but to get any help on serious topics like that or find good .NET samples your chances to find something in VB.NET are really low, so you really want to be able to at least read and compile C# code, anyway.
Please see this discussion and references on this page:
OCR Software[
^].
—SA