Write it. Do the hard work and stay up late working on it. (That part should come easy ;-) ). Put yourself in the position of the beginning C# developer who understands the fundamentals of software -- OO, data types, inheritance -- and is new to C#. Write it with him or her in mind. The words will pour out. And one day, a year or less from now, your name will be there with the other authors.

I already have one book to my name and contributed on another. My book writing days are over. I teach and write courseware...