I've moved your post to the Certification forum.
Here's the roadmap doc for the DCA exam - http://communities.vmware.com/docs/DOC-12751.
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Exam is quite hard.... due to the lot of task to do in a limited time (see the blueprint for more detail on number of question and time).
I suggest to make a lot of labs.
PS: thread moved to DCA area.
lot of lab and clever management are the two key things ..