is the Kathey Sierra book is enough to get the good secore in SCWCD??
That's really dependent on you: what experience you have, how you get on with the book, how much depth you want to get into, and what you consider a "good score". Though in my opinion, since the exam costs considerably more than any books,
you should try the book first and see how you go, then decide if you need to supplement your learning. The SCWCD should be about becoming proficient with the technology (to the point you can just write and deploy a web app without any references), and not just about the score on the exam. If you find you can't jump straight in with a cert book, or if HFSJ doesn't give you the depth you would like, then you will need to look further afield.
Charles Lyons (SCJP 1.4, April 2003; SCJP 5, Dec 2006; SCWCD 1.4b, April 2004)
Author of OCEJWCD Study Companion for Oracle Exam 1Z0-899 (ISBN 0955160340 / Amazon Amazon UK )