If you are a Microsoft Dynamics CRM client or you are considering Microsoft Dynamics CRM, this is a good place to start.  From Microsoft:

Microsoft Dynamics CRM

Visit crm.dynamics.com.

The Microsoft Dynamics CRM Web site is the place to go for information on all things CRM. You’ll find everything from an introduction to CRM and its value to your business to white papers, product specifications, customer testimonials, links to CRM communities, and much more.

Resource Center

Visit rc.crm.dynamics.com/rc/default.aspx.

The Resource Center is a one-stop shop designed to help you get started, maximize your efficiency, and build your business. Using a community-centered approach, the Resource Center brings some of the best ideas via blogs, forums, and newsgroups right to your desktop. But if you like to explore them on your own, you’re just a click away. Ramp up now and gain the knowledge that will help you care for your customers and maximize profits.

Microsoft Dynamics CRM Online Video Gallery

Visit www.democrmonline.com.

The Video Gallery introduces you to the functions and capabilities of Microsoft Dynamics CRM Online in a visual, task-oriented style to help you learn how to use CRM Online to your full advantage.

Developer Center

Visit msdn.microsoft.com. Search for “crm developer center”. Click the first link: Microsoft Dynamics CRM.

The Microsoft Dynamics CRM Developer Center is the place to go for information and sample code for developers. You’ll find both introductory and in-depth articles, overview and reference documentation, entity model diagrams for you to download, links to community and support, and much more.

SDK Download

Visit msdn.microsoft.com. Search for “crm 4.0 sdk”. Click the first link: Microsoft Dynamics CRM 4.0 SDK.

The Microsoft Dynamics CRM SDK download package contains all the same documentation found in the MSDN library, as well as hundreds of code samples in both C# and Visual Basic .NET, code to build tools for registering plug-ins, and a design guide to help you create CRM add-ins that match the look of Microsoft Dynamics CRM.

CRM on the MSDN Code Gallery

Visit microsoft.com. Search for “code gallery”. Click the first link: MSDN Code Gallery.

The MSDN Code Gallery is your one-stop resource for finding code to customize and enhance your CRM experience. Developers and software vendors can start here to find code solutions.

CRM on CodePlex

Visit codeplex.com. Search for “CRM”.

CodePlex is the Microsoft open-source, project-hosting Web site. Developers and software vendors can start a new project, join an existing one, or download software created by the community.

Accelerators for Microsoft Dynamics CRM

Visit codeplex.com/crmaccelerators.

CRM Accelerators are a range of add-on solutions developed for Microsoft Dynamics CRM 4.0 customers and partners. These ready-made solutions include event management, sales forecasting, service, notifications, and analytics. The accelerators are available at no cost and showcase how the Microsoft Dynamics CRM 4.0 platform can be configured and extended.

Implementation Guide

Visit microsoft.com\downloads. Search for “crm implementation”. Click the link: Microsoft Dynamics CRM 4.0 Implementation Guide.

The Implementation Guide contains comprehensive information about how to plan, install, and maintain Microsoft Dynamics CRM 4.0. The planning tools include over 40 templates, projects, and worksheets to help plan your implementation.

Mobile Express for Microsoft Dynamics CRM 4.0

Visit microsoft.com/downloads. Search for “crm mobile express”. Click the link: Mobile Express for Microsoft Dynamics CRM.

Mobile Express for Microsoft Dynamics CRM gives users access to Microsoft Dynamics CRM data through a Web browser on a mobile device. Mobile Express for Microsoft Dynamics CRM is installed on the server, not on the mobile device. The current release of Mobile Express for Microsoft Dynamics CRM 4.0 is available in English only.

Community Home Page

Visit community.dynamics.com/crm/home.aspx.

The Microsoft Dynamics CRM Community is the place to go for information about all things CRM. You’ll find articles and links to blogs, forums, newsgroups, MVPs, and much more.

Team Blog

Visit blogs.msdn.com/crm.

The Microsoft Dynamics CRM Team Blog is the place to go to get to know and connect with the CRM team. You’ll find posts on customization, development, and implementation.

Team Blog Specifically for CRM Online

Visit blogs.msdn.com/dynamicscrmonline.

The Microsoft Dynamics CRM Online Team Blog is the place to go to get to know and connect with the CRM Online team. You’ll find posts on many hot topics, including Windows Live ID, code samples, and customizations.

Forums

Visit social.microsoft.com/forums. Scroll down to the Dynamics section.

The Microsoft Dynamics CRM Forums are your question and answer resource. You’ll find answers to many of your most pressing questions and a team of crack experts ready to help.

MVPs

Visit microsoft.com. Search for “mvp”. Click the first link: Microsoft Most Valuable Professional.

The Microsoft MVP site recognizes exceptional technical community leaders from around the world. Here you can find experts who love to talk about all aspects of Microsoft Dynamics CRM.

CRM on Facebook

Visit facebook.com. Search for “Microsoft Dynamics CRM”. Click the link: Microsoft Dynamics CRM.

The Microsoft Dynamics CRM group in Facebook is a community that facilitates networking and collaboration. Go here to meet people in your part of the world, view videos, and introduce your company to the group.

CRM on LinkedIn

Visit LinkedIn.com. In the group directory, search for “Microsoft CRM”. Click the link: Microsoft Dynamics CRM.

LinkedIn.com and the Microsoft Dynamics CRM group is a community that fosters business networking. Here you can place a public resume, create and maintain business connections, and provide feedback to business acquaintances.