The NCLEX is taken at the end of the program - usually after graduation, depending on the state. A great place to start for NCLEX information is
www.ncsbn.org . Those are the makers of the exam. Their 2006 Candidate Bulletin (a PDF file) is particularly helpful. PearsonVue is the testing company that administers the tests. Their website is
www.pearsonvue.com/nclex .