Is there any book available for studying Ubuntu SDK. The documentation may be enough, but it lacks a real flow. After the introduction chapters it becomes a bit confusing. I really want to do application development on Ubuntu and I am not getting from where to study about QML and the Ubuntu SDK. Is there any PDF version of the cookbook available at here?
For more info, check out Ubuntu App Developer Resources Cookbook
You may also look at Introduction to Web Applications Development Guide
The Mono Project
Also check out The Ubuntu App Developer Cookbook Announced
As far as a PDF, I can't find any at this time. That doesn't mean that it might not be available later.
Source:Ubuntu App Developer
(I know this doesn't directly answer your question about a PDF version of the Ubuntu App Development Cookbook, but hopefully it will help you get started developing for Ubuntu Touch)
For learning the Ubuntu Touch SDK, I'd study the Ubuntu SDK documentation.