The book Differential Forms in Algebraic Topology of Bott & Tu gives a nice treatment with the Thom isomorphisms and the Euler classes of vector bundles rank $2$. However, I think their approach to the Euler classes in higher dimensions is quite terrible for novices, at least for me because I do not want to be swamped in a bunch of Čech cohomology stuffs and bicomplexes-arguments.
Therefore, I found another book, Differential Geometry: Connections, Curvature, and Characteristic Classes of Tu in which the author represents Pontryagin, Euler and Chern classes from differential geometry point of view unlike topological methods in Bott & Tu. In particular, he (Tu) constructs the Euler class by mean of curvature matrix and Plaffian but I do not know why he just stops at giving the definition without proving other important axioms characterizing the Euler class as other books do. So I ask for a book doing this job.
Thank you in advance.