The required textbook is Available from Amazon.
Modern Operating Systems: Global Edition (4e)
Andrew S Tanenbaum & Herbert Bos
Edition 4
ISBN 13: 978-1292061429
ISBN 10: 1292061421
Published 2014 by Pearson Higher Ed USA
If you don't already own a copy, and face it, as CS Majors you really should be sleeping with this under your pillow, I strongly recommend you get hold of the definitive guide to ANSI C by the gentlemen who not only "wrote the book" on C, but in Dennis Ritchie's case, wrote the language itself.
The C Programming Language, 2nd Edition
Brian W. Kerhnigan & Dennis M. Ritchie
ISBN 13: 978-0131103627 ISBN 10: 0131103628
Published 1998 by Prentice Hall