Books on Quantum Measurement I have been trying to understand clearly the concept of non locality, hidden variables, quantum measurement etc through research papers. I also read Quantum Theory and measurment by Wheeler and Zurek but I feel I've got nothing into my head. 
Please recommend some introductory books on above mentioned topics for beginners.
 A: Lectures on Quantum Theory: Mathematical and Structural Foundations by Chris Isham is a thin, easy to read book. The first 6 or so chapters are a simple introduction to quantum mechanics, but from about chapter 7 or 8 he goes into the Quantum Measurement problem and various interpretations and their associated difficulties. He also discusses Bell's Theorem, Gleason's Theorem and other results. It does not go very deep, but I found it to be an excellent beginner's introduction.
A: Most papers on quantum mechanics don't explain issues like interpretation clearly and non-locality clearly. The most notable exceptions to this are David Deutsch and to a lesser extent David Wallace.
"The Fabric of Reality" by David Deutsch is a popular book that explains quantum mechanics, see especially chapter 2. See also "The Beginning of Infinity" by Deutsch, Chapters 11 and 12.
If you are willing to do a little matrix algebra you might want to try his lectures on quantum computation:
http://www.quiprocone.org/Protected/DD_lectures.htm.
Deutsch has also written two papers explaining why quantum mechanics is entirely local:
http://arxiv.org/abs/quant-ph/9906007
http://arxiv.org/abs/1109.6223.
You might think that Bell's theorem implies non-locality but it doesn't. Bell's theorem explains that if you had a theory that describes the world using stochastic variables, then to reproduce Bell type correlations it would have to be non-local. But a quantum mechanical system is described by an algebra of Hermitian operators, not by stochastic variables. So Bell's theorem doesn't imply that quantum mechanics is non-local.
David Wallace also has some papers explaining various issues such as the measurement problem:
http://users.ox.ac.uk/~mert0130/papers-ev.shtml.
A: I believe Travis Norsen's book 'Foundations of Quantum Mechanics' does a good job of presenting the main interpretations and arguments in a more or less agnostic way. If you like the many-worlds interpretation you should look at David Wallace's 'The Emergent Multiverse' for a (very!) thorough technical account of it, or perhaps Sean Carroll's 'Something Deeply Hidden' for a popular account. You can also find interesting discussions in the writings of Scott Aaronson, such as here and here.
A: I would recommend Asher Peres: "Quantum theory: concepts and methods" on this subject. It sets out concepts and methods which have proved their worth in elucidating quantum theory fundamentals, whereas some of the books I see mentioned in other answers here are efforts of salesmanship for their author's preferred way of approaching quantum mechanics.
