"Total Workday Control Using Microsoft Outlook" by Michael Linenberger
We use less than 10% of Outlook fonctionnalities. I had tried to use Outlook following the GTD method and it was a failure each time.
Linenberger's book allowed me to customize and use Outlook in the right way.
My In-box is empty most of the time, I only get the right tasks at the right time, I know how to file my E-mails, I quickly can follow up my delegated tasks etc, etc.
His chapter about how to delegate projects (never never never try delegating anything bu sending "task" to people through Outlook !) and follow them up makes a lots of sense and is not very far from what I have learned through Manager Tools.
It requires no special skills (I am no computer fanatic), it is easy to understand (the reading was easy for a French guy). It just requires some time to "program" Outlook so it looks the way it should (2 hours). You also will need to sometimes to get back to the book.
In conclusion, this book will allow you to transform your Outlook into a very good tool helping (just helping) you applying GTD and some of the Manager tools principles !
A real good investement ...