I agree with Hannes, get a book on general OOP practices. Most books will teach you language independent OOP concepts that apply to VB, C++, C#, Java, etc... Because once you understand the general concepts behind OOP, it's easy to apply them to just about any programming language.

EDIT: Hmmm... it seems I have never looked over a book that covers OOP in a more formal sense. Maybe I will follow this thread and find one for myself! haha