Urgent : How to authenticate and retrieve data from Microsoft Dynamics CRM 2011 (Web)

Hello All,

I am new to Microsoft Dynamics CRM. I added SOAP service reference in my project like "https://SERVERNAME/XRMServices/2011/Organization.svc" named "MicrosoftDynamicsCRMSoapService" and I am able to create client object as :

MicrosoftDynamicsCRMSoapService.OrganizationServiceClient organizationServiceClient = 
new MicrosoftDynamicsCRMSoapService.OrganizationServiceClient();