You must study from the NCERT books first. Most of the questions in NEET Exam are asked from NCERT books.
NEET Exam is one of the toughest exams in India. So, prepare yourself well for the exam.
If you want to appear in NEET 2018 Exam then you must register yourself first. You can fill you NEET Online Application Form on or before 09th March 2018.
For NEET preparation you must solve previous year question papers and take online mock tests. This is the best way to prepare for the exam as you will get to know the pattern and difficulty level of the questions.