Can anyone help me to find a simple and good reference (a book, lecture notes or a website) for learning the [surgery theory](https://en.wikipedia.org/wiki/Surgery_theory) and its applications? I seek a reference together with many examples and figures for more intuition.


Thanks.



A simple and good reference on surgery theory
Well, there's surgery and there's Surgery Theory. By the former, I mean the basic geometric and homotopy-theoretic ideas that went into building a big machine (the latter) to systematically study problems in high-dimensional manifolds. Although you can dive right into Surgery Theory, I think it's much better to invest some time in learning the basic ideas, from the original paper of Milnor (A procedure for killing homotopy groups of differentiable manifolds. 1961 Proc. Sympos. Pure Math., Vol. III pp. 39–55). The introduction to Ranicki's book referenced above makes the same recommendation. The basic `example' is the application of surgery to classifying smooth structures on homotopy spheres (Kervaire-Milnor, Groups of homotopy spheres. I. Ann. of Math. (2) 77 1963 504–537.) 


After that, it may be reasonable to start learning the more systematic version, which was formulated by Browder-Novikov-Wall (and many others). Ranicki's book is a good place to start with this, but if you really want to understand examples, you will at some point need to read Wall's book on non-simply-connected surgery.


