There are no any official materials. Please check following thread http://forums.adobe.com/message/4935964#4935964 in the forum there are some example question and general information about CQ certificaiton.
On the website (http://training.adobe.com/certification/exams/cq-5.5-component-developer.html) it is stated:
I can confirm, you should have done some project work with CQ5 to pass this exam. Although the trainings help, there are questions where only experience will help you. So I do not advise a CQ5 newbie to take this exam within the very first months.
Have you looked at the Exam Guide? That lays out the complete list of topics covered by the exam.
Jorg is correct that it is ideal if you have at least a year of actual project experience. If this isn't feasible then you will need to construct synthetic projects which cover the topics listed in the exam guide. The trainings offered by Adobe will help as well.
Thank you for the Replies.
I checked out the exam guide.
These topics are sounds familiar to me.
Issue is that I don't know depth of these topics.