Below is a link to a very descriptive and easy to use code for adding Header and Footer in a PDF file while using the iTextSharp library .
http://www.mazsoft.com/blog/post/2008/04/30/Code-sample-for-using-iTextSharp-PDF-library.aspx#
308c74bb-cd4c-4b70-917d-3bf4b7865953|0|.0|96d5b379-7e1d-4dac-a6ba-1e50db561b04
iTextSharp
PDFiTextSharp