Microsoft does a great job of documenting applications. We use these guides often during training for new admins and power users.  

Product Documentation

· Microsoft Dynamics CRM 4.0 Implementation Guide http://www.microsoft.com/downloads/details.aspx?familyid=1CEB5E01-DE9F-48C0-8CE2-51633EBF4714&displaylang=en

· Microsoft Dynamics CRM 4.0 Server Readme http://www.microsoft.com/downloads/details.aspx?familyid=1DB2D16D-7885-4561-A461-20B948913B3F&displaylang=en

· Microsoft Dynamics CRM 4.0 E-mail Router Readme (On-Premise and Microsoft Dynamics CRM 4.0 Service Provider Editions) http://www.microsoft.com/downloads/details.aspx?FamilyId=C54B428B-3565-4037-B4F3-C553F3288C45&displaylang=en

· Microsoft Dynamics CRM 4.0 Software Development Kit http://www.microsoft.com/downloads/details.aspx?familyid=82E632A7-FAF9-41E0-8EC1-A2662AAE9DFB&displaylang=en

· Microsoft Dynamics CRM 4.0 Logical Database Diagrams http://www.microsoft.com/downloads/details.aspx?familyid=B73912E8-861E-43AE-97B4-72B3E809F287&displaylang=en

· Developing ISV Applications using Microsoft Dynamics CRM 4.0 http://www.microsoft.com/downloads/details.aspx?familyid=1217EFFF-BE8F-4AC8-8E32-AF367305FBA9&displaylang=en

· Microsoft Dynamics CRM Developer Center http://msdn.microsoft.com/en-us/dynamics/crm/default.aspx

Books

· Microsoft Dynamics® CRM 4.0 Step by Step http://www.microsoft.com/MSPress/books/12643.aspx

· Working with Microsoft Dynamics™ CRM 4.0, Second Edition http://www.microsoft.com/mspress/books/10598.aspx

Community Resources

· Microsoft Dynamics Resource Center http://rc.crm.dynamics.com/rc/regcont/en_us/opdefault.aspx

· Microsoft Dynamics CRM Technical Community https://community.dynamics.com/crm/home.aspx

Training

· Microsoft Dynamics Sure Step information available on PartnerSource (registration required) http://go.microsoft.com/fwlink/?LinkID=88066

· Available on PartnerSource (registration required)  https://mbs.microsoft.com/partnersource/training/

· Available on CustomerSource (registration required)  https://mbs.microsoft.com/customersource/training/