If you're looking at migrating data into Salesforce or Dynamics CRM then Scribe Insight is one of your options. Its an integration system like SSIS and many others but its known for its particularly good support for cloud CRM systems.
If you've only ever worked with Web Services in Dot Net, you could be forgiven for expecting it to be easy to use Web Services to interface with other platforms. In Visual Studio, it's all a bit Fisher-Price: you define your Web Methods, then add a Web Reference to the client and everything ticks along nicely. You don't even see any XML.