I came to this site during my time leading up to the TEAS test, and I found it very encouraging to hear from others about their experiences. This test can be stressful, so I want to let you know what I did and how my strategy resulted in success.
Late October 2012: I took the online practice test (test A) from ATI's website and I failed miserably. I got a 58% average, with science being the most challenging. ATI gives you "Topics to Review" and I used these to help me study the areas in which I need to improve upon. NOTE: The online test is WAY MORE DIFFICULT than both the book tests and the actual test, but I didn't know this at the time.
December 2012 to February 2013: I studied the official TEAS V study manual until the pages were starting to rip! I took the practice tests in the book once I thought I was prepared and thankfully I did a lot better on those tests. I even bought the McGraw Hill 5 TEAS tests book and used them for practice (they're fairly similar to ATI's). I was passing all of those tests, even the science sections. (It helped that I understood human anatomy and that I'm currently taking bio-chemistry and physiology. Those classes really help with TEAS prep.)
February 2013: As a confidence booster, I decided to retake the online test. I absolutely didn't remember anything about that test so I thought I would take that and use it as an indicator of my test preparedness. That was a mistake! I got an overall average of 73% but the science was still holding me back. I passed reading, math, and English, but the science was insane in terms of its content. Those science questions were nothing like ATI nor McGraw Hill's book tests! Yes, some of the questions seemed like they were designed after the study material, but many were very difficult and I was left scratching my head. I was very depressed at this point. I couldn't understand (and still don't) why ATI would design practice tests that were so different from one another. How was I to know which test would be like the real one?
February 22, 2013: I decided to take the real one despite that result with the online test. I passed with an 85% average which put me in the 95th percentile for the nation! The real test is EASIER than the practice tests! The reading, math, and English are pretty comparable to the book tests, but the science is still the hardest part. In other words, if you can pass the practice tests then you can pass the real one.
Summing up: 1) Give yourself plenty of time! Don't wait until the last minute. One month is probably not enough time unless you're super smart to begin with. 2) I would buy the ATI study manual and the online test (the online tests are way more difficult but they paint a picture of your weak/strong areas). 3) STUDY THAT BOOK! If you had an open book test, you would pass without a problem; however, some questions would still seem like a mystery. 4) Take the book tests (even the McGraw Hill if you want more practice). 5) If you can pass the book tests then take the real one. Many people, myself included, think the real test is easier.
I hope this helps some of you. No matter what, be diligent and don't get discouraged!
John