Software in C#

Hi,

I would like to receive help because I wish to try a software. My purpose is to develop an application and I have some experience in C and C++. The thing is that I found ready made sample programs on a site (http://www.voip-sip-sdk.com/) and wanted to try them out. As I have seen the sample programs are developed by the help of a software called Ozeki VoIP SIP SDK. The trouble is that for developing C# knowledge is needed and I do not have experience with it. Can you help me with this? Are there any good tutorials or books to learn C#, or should I try Visual Studio? I appreciate your help and answers.

I have a hunch that you probably should ask this on a site that has something to do with C#.