These are a little old, as in published on 21st July 2006, but still great step by step guides on how to ensure that servers and clients connected to them are secure.  They do not just look at SBS 2003, but also Windows 2000 & Windows Server 2003 server environments too.

How to Configure Windows Firewall in a Small Business Environment using Group Policy.doc

How to Configure Windows XP SP2 Network Protection Technologies in a Small Business Environment.doc

Securing Internet Information Services 6.0.doc

Link to Download details: Small Business Security Guidance

ttfn

David