This really is an excellent book for those wishing to develop Excel applications. It provides clear and useful information on the workings of Excel spreadsheets and how to interact/control them in VBA. Although I have over 12 years of Access VBA experience, my Excel abilities are far less robust. This book really does cover most of the bases: beginners will be pleased to know that there is a good introduction to the basics of VBA in early chapters, whilst more experienced developers will find a multitude of hints and tips to improve their applications. Topics include VBA fundamentals, the structure of Excel files, User forms, Object Oriented coding, coding charts and pivots, integrating with other Office apps, including help files and much more.
There is a nice glossary of VBA commands and functions in the back with one line explanations which you can then take further by looking up the details via the index, and it comes with a CD of code samples.
Is it perfect? No. There is very little on interfacing Excel to external data sources using MS Query for example, and only 1 page on considerations when making the application cross platform with Mac Excel (although Office 2011 for Mac with VBA support has only just been released, Office 2004 for Mac does have VBA too, so a little more would have been nice. Not all Mac users use Office 2008).