Good morning Raghavan,
1. To what extent does the book cover on the Web Server, HTTP Semantics?
The book introduces the HTTP protocol and discusses how a web application communicates with a web server. I think this should give a good understanding of the underlying architecture to beginners.
2. Does it cover the fundamentals of Server side programming with the web server and its needs?
Absolutely, I think all good servlet/JSP books do cover these topics.
3. Though it is more of advanced/latest version of Servlet (3.0) and JSP (2.2), to what extent it will serve as a complete reference to Servlet and JSP? To put it in other way, will it be a single point of source for a beginner to pick up and excel?
The book covers all servlet/JSP features, including the new features in Servlet 3.0 and JSP 2.2. So yes, this book is also for you if you have no experience with servlets.
4. Does this book touch base on the portability of code across different containers? I guess you might have taken Tomcat as an example as most people do.
Yes, I used Tomcat to test the examples. However, servlet/JSP applications will run on any compliant Java EE or servlet/JSP container. So I don't think portability is an issue.
5. Does it also give a decent introduction of XML and XML Schema for the DD (web.xml) file if at all a developer is still going with the web.xml written by him?
The deployment descriptor (web.xml) and web fragments are discussed extensively. However, the reader should already know basic XML.
Hope these answered your questions.