A useful book for the material on characteristic classes, as well as cobordism, is Characteristic Classes by Milnor and Stasheff, which should be available in the CooP. The second edition has some material on K-theory also.
Allen Hatcher has made available the first part of a work-in-progress, a book called Vector Bundles and K-theory. It is available from his home page, as a PDF file of about 100 pages. Also there is his excellent book, Algebraic Topology (a PDF file of about 4MB). A printed version of this book is in the works at Cambridge University Press.