You have a few options:
- Use the Salesforce API and build a wrapper yourself. You need to setup developer account etc.
http://www.salesforce.com/us/developer/docs/api/index.htm http://www.maatech.com/dotnetframework/using-salesforce-com-in-c.html
- Use a 3rd part DLL to connect to Salesforce and make it easy to work with Salesforce objects. Most of the DLLs are paid versions with trial facility.
http://visualstudiogallery.msdn.microsoft.com/a639fe58-54b6-429b-b875-1584c365afb7 http://visualstudiogallery.msdn.microsoft.com/f6ecab53-dec5-4aca-b559-ce39315f6781