PDFsharp & MigraDoc Foundation

I am new to pdf sharp and a bit confused on how to do some stuff.

I have figured out how to create the top bit of my pdf document the problem is that after that bit has created I then need to insert a string that the user has entered and this string could be as long as the user wants so I have no idea how to copy the string in and format it and add new pages to the document if it extends over the first one. I also need to add some stuff to the end of the string once it has done but have no way of getting the x, y coordinates so that I can do this.

Can anyone provide some starting points on where to start.

Thank you very much for all replies.