This page on the CUNY website gives you information about preparing for the CUNY Assessment Tests (CAT) in writing, reading, and math : CUNY Assessment Tests and includes some practice exercises and sample questions.
Here are some practice writing exercises for the CATW (writing test).
CUNY's student handbook all about the CATW.
Information about the CATR (reading test) that includes some test-taking strategies, tips, and common errors to avoid.
John Jay College has put together some great resources that can be used by students in any CUNY college. They include practice questions and explain why each answer is preferred by the test evaluators.