The best way to learn is to fire up excel, or whatever version of VBA you're going to use (yes they are subtly different). Turn on the macro recorder, do some stuff, stop recording and then look at the code created. You'll immediately see some of the classes created, they can be looked at in more detail using the Object Explorer within the VBA environment. The syntax is just like any basic language. A couple of good practises, put the line 'Option Explicit' at the top of every source file, if not variables don't need to be declared, which is initially easy but leads to annoying bug hunts.
I'm not aware of a one stop shop to learn VBA, as you've already got programming experience it'll be a matter of unlearning some stuff - like OO, inheritance etc (yes I know VBA supports classes and interfaces but they're not the full enchilada).
BTW I noticed you tagged this as VB.Net, unfortunately VB.Net is not VBA - they're not related at all. Similarly VB and VBA are not the same although the overlap is about 90%.