Adam Conkle has published some great troubleshooting, tips and tricks and how to articles on TechNet that should help you in evaluating and implementing Active Directory Federation Services.
AD FS - How to invoke a WS-Federation sign-out
AD FS 2.0 - Prompted for credentials when you are expecting to be allowed anonymous access
AD FS 2.0 - How to set the Primary Federation Server in a WID Farm
AD FS 2.0 - The Admin event log shows Error 111 with System.ArgumentException: ID4216
AD FS 2.0 - Browsing to Federation Metadata fails "Unable to download federationmetadata.xml"
AD FS 2.0 - Continuously prompted for credentials when using FireFox 3.6.3
AD FS 2.0 - How to configure the SPN (servicePrincipalName) for the service account
AD FS 2.0 - Continuously prompted for credentials while using Fiddler Web Debugger
AD FS 2.0 - "Script is disabled. Click Submit to continue."
AD FS 2.0 - How to enable and immediately use AutoCertificateRollover
AD FS 2.0 - How to perform an unattended installation of an AD FS 2.0 STS or Proxy
AD FS 2.0 - The AD FS 2.0 Windows Service fails to start - Event 102 and 220 logged
AD FS 2.0 - How to manually run the AD FS 2.0 Initial Configuration
-- Jonathan "Ned's Blog Monkey" Stephens