High-level recap, you will need:
a) 36 months of project management work experience within the past eight years (or 60 months if you don't have a 4-year college degree). (The 4500 / 7500 hours requirement no longer applies).
b) 35 hours of qualified project management training
 

The test is described on PMI's web site. As a high-level recap:
a) The test consists of 180 questions which must be completed in 230 minutes (just under 4 hours).
b) Most questions are multiple-choice, with four choices.
c) There is no penalty for incorrect choices, so leave no question unanswered.