Have you bought an official CS4 licence too?
The best way to learn a programming language/environment is to actually use it and make something with it. And that something should better be interesting/fun. I would suggest you try to create a simple game with it and when you face problems, search for solutions in your e-Books or on the internet.
Try the basics first, like simple animations, manipulating frames, tweening, etc.
Then, if you have a programming background, actionscript wouldn't be too hard.
Just master the main syntax, then you can rely on Flash's F1 for the rest.
Those 2 books should get you started.
I've also bought a book on flash CS4 and I'm half way through now.
There are some decent basic tutorials on youtube
I learned by downloading tutorials and just repeating that they did he he. that is how i learned.
Read the fundamentals, then try and err, have some fun, then start your project.
Edit: don't spend money with the initial thing. Have a look at w3schools.com first, at the flash section.
What are you trying to learn in Flash? Just normal Flash videos, or the coding part of it. I don't think half the people that use Flash know about the coding part. Actionscript is very powerful, and pretty fun and easy to use.
I've either taught myself or taken classes on Actionscript at school, but I'm hoping next year will be C++.