Even those simple-looking "21 Days" style books work fine for a quick lead-in to VB.
They should cover the basics of the language syntax, working with the GUI form-layout tools in the IDE, setting control properties, manipulating methods and properties of VB objects, menus in VB, the event-handling mechanism VB uses, and simple I/O. Maybe even some simple graphics processing.
But this is for a quick intro, enough to be able to make sense of a more advanced book. This first level book will be boring, but it isn't the waste of time some people might tell you it is. Go through it methodically, beginning to end being VERY sure to actually do all the simple example programs.
Then get a next level book, covering database access, advanced I/O topics, classes, ActiveX, and socket and serial port I/O. Perhaps advanced graphics processing if you have a use for it. These books usually have something like "Mastering" in their titles - but quality does vary.
My "best" choice isn't a book at all, it is Microsoft's "Mastering VB" CD short-course.
After this you'll find you know merely enough to be dangerous - you have all of Windows DNA (and soon .Net - the next incarnation) ahead of you.
I'm assuming you need more than to do simple two-tiered applications. If not, you'll be almost home after the second book - if you supplement it with a book that discusses VB and SQL Server. You might need more detail on SQL Server if you're going to have to be the DBA too, or if you need to write stored procedures. Transact-SQL is very different from Oracle's PL/SQL, but meets roughly the same needs.
You might want to look into reporting tools beyond those included in VB too, but you won't need that immediately.
That's my 2 cents, I'm sure others have more specific recommendations to make ;-)
