It is worth to note that SUSY model now is in doubt, because of the LHC experiments. It is growing consensus that it is probably wrong at least as regard to supersymmetry, although it may not have influence on mathematical apparatus behind of it,which is worth of knowing of course.

I suggest to check Steven Weinberg "The Quantum Theory of Fields" Vol 1,2,3 - http://www.amazon.com/Quantum-Theory-Fields-Vol-Foundations/dp/0521550017