MSMQ and WCF: Getting Started
Windows Communication Foundation (WCF) provides a powerful programming model to develop service-oriented applications. MSMQ integrates very well with WCF so queued applications can be developed using WCF. WCF provides two bindings that support MSMQ - NetMsmqBinding and MsmqIntegrationBinding. NetMsmqBinding provides asynchronous communication between WCF endpoints. The MsmqIntegrationBinding enables a WCF endpoint to communicate with an existing MSMQ application written in C, C++, COM, or System.Messaging APIs.
Here's a list of some useful resources to help you get started.