how to calculate spectral measure for a given normal operator for example right shift operator?

$\begingroup$ This looks like a homework problem, so don't be surprised if your question is closed  see the faq. You'll find a lot of information on how to calculate certain parts of the spectrum of certain operators in the book Reed/Simon: "Methods of Modern Mathematical Physics", Volume 4: "Analysis of Operators". $\endgroup$ – Tim van Beek Feb 6 '11 at 16:39
There is an example in
MR1483073 (98g:46001) Meise, Reinhold ; Vogt, Dietmar . Introduction to functional analysis. Translated from the German by M. S. Ramanujan and revised by the authors. Oxford Graduate Texts in Mathematics, 2. The Clarendon Press, Oxford University Press, New York, 1997. x+437 pp. ISBN:
The spectral decomposition for the unbd. operator $i d/dx$ can be computed from that of a multiplication operator via the FourierPlancherel transform. That's in Kato's book on functional analysis.
Another way is to compute first of all the polynomial calculus for your operator $T$, which sometimes is doable and then make a guess about how $f(T)$ looks like for say continuous functions f (of course you must then find a proof and show that if polynomials $p_n$ tend to $f$, then $p_n(T)$ goes to $f(t)$. If you send me an email, I can send you some examples.