I bought the first SBS2008 book that was released which was SBS2008 Unleashed by Eriq Oliver Neale and it was ok. But then the SBS2008 Blueprint book was published from SMB Nation and I found this book much easier to read and follow.
There are 2 Authors Harry B and Philip Elder , Philip is a SBS MVP and has a great blog which he keeps updated reguraly and of special interest is his SBS2008 Setup Checklist. It is currently on version 1.5 and I cant think of a better way of installing and configuring SBS2008.
You can see the setup guide here http://blog.mpecsinc.ca/2009/05/sbs-2008-setup-checklist-v111.html