One important thing that is often forgotten during/after the installation of Dynamics CRM is to properly set the SPNs for your service accounts (if necessary 😉 ).
Here are three links which I often take as reference when we plan new deployments:

• http://blogs.msdn.com/b/webtopics/archive/2009/01/19/service-principal-name-spn-checklist-for-kerberos-authentication-with-iis-7-0.aspx
• http://rc.crm.dynamics.com/rc/regcont/en_us/op/articles/configurespn.aspx#o45872
• http://blog.sonomapartners.com/2007/04/kerberos_and_de.html