However I felt the need for a reference book that discussed topics like AppArmour, SELinux, Encryption, FACL, Intrusion Detection etc.. for more advanced users. Well, I found one such book Ubuntu The Complete Reference.
Indeed the book lives up to its grandiose title and it does cover basis for new users and the advance users who are planning to run Ubunutu on desktop and servers would find it very useful too. While reading the book I felt that author could have covered a chapter in more detail, however given the wide range of topics (I dare say, just too many) that are already covered in this book, I felt it was asking for too much :) .
My kudos to Richard Petersen and technical editor Ibrahim Haddad for doing such a great job on this book and finish it too ! . The book is up to date covering Ubuntu Hardy Heron (8.04) and you need to have it on your bookshelf.