Today a very good whitepaper has been published on "Configuring Kerberos Authentication for Microsoft SharePoint 2010 Products".

It contains specifics for SQL Reporting Services (SSRS 2008 R2) and step-by-step instructions on how to setup kerberos for this

It also applies partially to MOSS and is one of the bests documentation I've seen yet. So if you think about configure kerberos for your SharePoint farm,
these documentations are a "must read" for you ;-)

Complete list of all Links to this topic:


Sharepoint 2010 (MSS2010):

- Configuring Kerberos Authentication for Microsoft SharePoint 2010 Products (White paper)

- Configure Kerberos authentication (SharePoint Server 2010)  (TechNet Library)

 

Sharepoint 2007 (MOSS):

- Configure Kerberos authentication (Office SharePoint Server)  (TechNet Library)

- Prepare to crawl sites that use Kerberos authentication (Joel Oleson Blog) 

 

Kerberos in general (TechNet):

- Kerberos Explained

- Kerberos Protocol Transition and Constrained Delegation

- Kerberos Constrained Delegation in ISA Server 2006

- Using Kerberos Authentication with SQL Server 2008 / R2

- Kerberos Authentication and SQL Server 2008

- Kerberos authentication for load balanced web sites

Blogs about Kerberos:

- Kerberos for the Busy Admin (Microsoft's official Enterprise Platform Support DS blog)

- Kerberos Authentication problems – Service Principal Name (SPN) issues - Part 1 (Microsoft's official Enterprise Platform Support DS blog)

- Kerberos Authentication problems – Service Principal Name (SPN) issues - Part 2 (Microsoft's official Enterprise Platform Support DS blog)

- Kerberos Authentication problems – Service Principal Name (SPN) issues - Part 3 (Microsoft's official Enterprise Platform Support DS blog)

- Kerberos Authentication and SharePoint Key Resources (Joel Oleson)

- Service Principal Name (SPN) checklist for Kerberos authentication with IIS 7.0/7.5 (MSDN Blogs)