I found a greate tutorial about implementing a typical Master-Detail iPad application with orientation management in C# based on the MonoTouch framework. Thanks to Mike for this great work, it helped me so much to get my work done.
http://mikebluestein.wordpress.com/2010/04/03/using-a-uisplitviewcontroller-to-create-a-master-detail-ipad-app-with-monotouch/