How can I find out more about my IWC?

Many years ago my grandfather gave to me a very fine IWC gold pocket watch. Now I have become interested in finding out more about the watch. Any suggestions of how to get information about model, production year, if it is a common or rare model, etc.

Picture link...

Photographs of the dial and movement will be most helpful and please include the case and movement numbers.

Thanks. I'm not sure how to upload pictures. Could you please explain to me?

I finally managed to insert a picture-link.