I would like to ask your help. The reason for this is that I want to build an own application. I have some experience in C. After doing a research I found a site (http://www.voip-sip-sdk.com/) which deals with development and has several ready made sample programs. I became interested and after reading a bit it said that the sample programs are developed by a software called Ozeki VoIP SIP SDK in C#. I do not have any knowlege regarding C# so that is why I ask you to help me. How to start learning C#? Do you know any good books, tutorials? Should I try Visual Studio first? Let me know what you think. Thanks and regards.