You might have bought the Princeton Review book already, but I preferred Kaplan. PR's book had two almost identical sections for the SSAT and ISEE, so it seemed like an overpriced waste of paper.
Princeton for English, Kaplan for math--because it explains how to approach the math problems you get wrong. Get the official SSAT guide for the best practice tests.
You can buy them both used from Amazon or Betterworldbooks for less than the price of one new book. A version that is a year or two old is nearly always virtually identical (except for the cover) to the current year's version
