I studied the ATI manual, McGraw Hill and bought the ATI online tests (version A and B). My thoughts are - the actual test has all the content from the study manual except the Science is much more detailed in the actual exam. Reading, Math and Grammar are pretty similar and straightforward to the ATI study manual. I did have one Math question on the Pythorgorean theorem - so know that in case! For Science, know all the material in the study manual, however, go on-line/youtube and review many of the topics in greater detail. Know mitosis and meiosis and the outcomes and how many cells are produced as a result, know scientific method/theories and critical thinking, static and kinetic energy concepts, punnett squares, chemical bonds, basic chemical equations, cellular biology/components, etc. Science is the toughest and hardest to study/anticipate in regards to the actual test. The online ATI tests are a little harder than the actual exam, the ATI manual questions are a little easier than the actual exam. For example, the reading (stories and questions) in the ATI study guide are more simple - the actual test the reading passages are much longer and the questions/answers not as simple (though not tough by any means). Overall, plan about 6 weeks of study (this is what I did) unless your a whiz in these areas. Make sure you've time yourself in taking the practice tests as this will help you in the actual exam. Lastly, sleep well, eat a good meal prior and think positive thoughts prior to taking the test!!