The book didn't get me through Flash 8 in 24hrs - but to be honest I didn't really expect it to. I think realistically you could work through it in a week, doing 2-3 "hourly" tutorials a day. I found that the book started off well, at a good pace, but certainly got much more difficult requiring a lot of concentration and effort. Some of the tasks I couldn't get to work as expected despite going over them time and again. This could be down to me or the explanations in the book, which occasionally seemed confusing. As the book progresses there is an assumption that you've remembered most preceding things - which isn't always the case. The tutorials on Action Scripting were the most difficult and lacked good explanations as to why you were typing in the code as requested. I felt a bit like a 'blind follower'. Maybe some basic book on Action Scripting at your side would help you on these pages, especially if your movies don't quite work out - you need to be able to troubleshoot the inevitable problems you encounter.
The sections on using the drawing and type tools are very good as it the background into fundamental animation skills - the book excels in these areas. Be prepared to stick at it and if necessary go over the tutorials several times. Flash is more difficult to learn than I expected and I know this book is really a taster of Flash.
Overall it's a good overview of the software and gets you up and running with most things. It's a jumping in point to the world of Flash 8. More screenshots would really improve the book.
At the start of the book I was a complete novice, by the end I was able to create simple Flash animations to embed into my websites and had an understanding of how to approach more complex tasks.