Websites:

Config Mgr sites
http://www.microsoft.com/smserver/default.mspx – SMS 2003 homepage
http://www.microsoft.com/systemcenter/en/us/default.aspx – System Center homepage
http://social.technet.microsoft.com/Forums/en-US/category/configurationmanager/ – Configuration Manager News groups
http://www.microsoft.com/events/series/technetmms.aspx?tab=webcasts&id=42364 – Configuration Manager webcasts
http://www.microsoft.com/systemcenter/configurationmanager/en/us/default.aspx – Config Mgr. homepage
http://www.myitforum.com/ – Great community
http://technet.microsoft.com/da-dk/configmgr/default(en-us).aspx
http://technet.microsoft.com/da-dk/library/bb735860(en-us).aspx
http://www.smsexpert.com/ – Information about MOF editing
http://www.1e.com/ – Config Mgr. addons

Deployment Sites:
https://blog.ctglobalservices.com/osdeploy/ – Deployment Blog, author Michael Petersen
http://blogs.technet.com/msdeployment/default.aspx – MDT Blog

Tools:
http://www.microsoft.com/technet/scriptcenter/tools/scripto2.mspx – Scriptomatic
http://sourceforge.net/projects/smsclictr – Config Mgr Client Center
http://www.myitforum.com/myITWiki/SCCMTools.ashx – SCCM Right click tools and more

Troubleshooting Management Point:
http://siteservername/SMS_MP/.sms_aut?MPCERT
http://siteservername/SMS_MP/.sms_aut?MPList

Other sites:
http://support.microsoft.com/default.aspx/kb/555638 – List of Active Directory attributes names to be used in system and user discovery

Administrator Console

Start the admin console in debug mode:
adminconsole.msc /SMS:debugview (the admin console is found in C:\Program Files\Microsoft Configuration Manager\AdminUI\bin folder)

For more information check – http://technet.microsoft.com/en-us/library/bb693533.aspx

Collections:

All Obsolete Clients:

select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System where SMS_R_System.Obsolete = 1

All Inactive Clients:

select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System where SMS_R_System.Active = 0

All Clients without a Config Mgr. Agent installed:

select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System where SMS_R_System.Client is null