I found this book very useful. With other material in the field the author did a great job.
If you planned to roll out a PKI just take a moment and take a deep breath before doing that and consider all the do's and don't's. Ask yourself the question if PKI is really the only solution for your problem. This book helps you get that perspective. Good style of writing, clear and consistent. Certainly worth buying. Don't assume this is a deep technical drill down on PKI and you're okay!
Rob Faber, CISSP, MCSE, Infrastructure Architect
The Netherlands