Did you study Chinese before?  For how long?  People with one year of Chinese knowledge can successfully pass the HSK 4 if they study and practice seriously.  I understand it takes a while to learn how to write characters, so a year and a half may be more realistic for some.  Any book done by Han Ban is good.  Just work on looking at pictures and trying to describe them, and know some basic grammar rules.  Seriously, the test isn't hard at all. They've made it simple so foreigners can "qualify" to study in the universities here.