Early in this blog's life I mentioned a book on MonoTouch that acts as a great intro to developing for iPhones with the MonoTouch framework. Or at least it did at the time. MonoTouch requires use of Xcode and things have changed quite a lot with the new Xcode 4 and MonoTouch 5 - I'm not sure if the book has been updated as yet.
Anyway, the principal author, Wallace McClure, has since been hard at work with Mono for Android and is on the cusp of releasing a book on working with the current version of Mono for Android, getting to grips with all the key aspects of Android development using the Mono for Android framework. The book is called Professional Android Programming with Mono for Android and .NET/C# by McClure, Blevins, Croft, Dick & Hardy, and is published by Wrox. You can pre-order it at Amazon – the amazon.com and amazon.co.uk links are below: