Moving to CS4

The good news is that the software hasn't changed all THAT much as long as you stick with actionscript 2 with new version of flash that you now have.  You may have to look for some of the interface features, for example the property inspector and library both look a little different, but most things work more or less the same.  That said, by all means don't stop with the book that I put together for  class; that's just the beginning!  

Did you receive documentation with the software? That may be a good place to start. Dreamweaver, for example, used to come with some great tutorials built in. I know that the new version of dreamweaver now has a really easy way to put in dropdown menus and probably handles css better and Flash now has a (supposedly) better way of tweening that I haven't used yet so there are new things worth learning.  

As for books, I have had good luck with the missing manual series for dreamweaver, and always buy the latest "Flash Bible" whenever I move into a new version of Flash. 

And, of course, there is a lot of good stuff online that can be found by googling.