NOTE: I will update this post periodically.

Although my focus is on Dynamics CRM 2011 as a development platform, I get asked about Administration resources all the time.  Basically, you need the fundamental admin skills required for the underlying technologies Dynamics CRM 2011 builds on: Windows Server, SQL Server (including Reporting Services), IIS, and understanding of how CRM Connects with Exchange and Active Director and then the CRM 2011 specifics.  Here are a set of resources I typically point people to:

Microsoft Dynamics CRM 2011 Implementation Guide

Microsoft Dynamics CRM 2011 Administrator's Guide

Book Review: Microsoft Dynamics CRM 2011 Administration Bible

System Center Monitoring Pack for Microsoft Dynamics CRM 2011

Optimizing and Maintaining the Performance of a Microsoft Dynamics CRM 2011 Server Infrastructure

There’s also a Microsoft Learning online courses one might want to take:

Collection 80296: Installation and Deployment in Microsoft Dynamics CRM 2011

These resources should give you a sense for what it takes to be a CRM 2011 Admin. 

@devkeydet