MSDN: Developing Office Applications Using VBA
If you haven't taken a look at it already, you can learn a lot from Visual Basic help within Office. To access it open an Office program and press Alt+F11 to open the Visual Basic Editor. Then press F1 or navigate to Help -> Microsoft Visual Basic Help. Also, as Mitch mentioned, if you learn the basics of VB6 you can use the same syntax for VBA.