Additional steps required after running the SharePoint Products and Technologies Configuration Wizard to enable Trusted sites and automatic User Authentication for Central Administration.
André Vala has a great series on developing features for deployment to SharePoint.
This is a great doc from the Office site which you can use to help plan your SharePoint / MOSS service and content access accounts.
As an update to my post about Configuring the Sharepoint MOSS Single Sign-On Service, I’ve discovered that the SSOADMIN user (the user account which the SSO service is run under) requires that the user account is granted the “Logon as Service” permission directly, rather than it being inherited by Group memberships or some other means.
Configure Single Sign-On (Office Sharepoint Server) Creating a Service Account http://www.sharepointblogs.com/llowevad/archive/2007/06/25/sharepoint-2007-single-sign-on-setup.aspx