
NCLEX (National Council Licensure Examination) is a nationwide examination for the licensing of nurses in the United States and Canada.
For a sense of what content is covered by the test, you will want to look at the Test Plans put together by the National Council of State Boards of Nursing (NCSBN).
NCSBN has lots of useful information that may help you prepare for the text. Continue through the rest of their website after looking at these pages:
Taking the NCLEX
How the NCLEX Works
What the Exam Looks Like