I took the Teas V about six months ago (twice). I prepared about six weeks beforehand for the test. I bought the ATI book and ATI on-line practice tests. These are "golden" and I'd recommend purchasing these as a start. I have a bit of test anxiety, and when I took the test the first time, I spend a little too much time on the Reading portion of the test (and sadly there was a distraction at my testing site at the time) and ran out of time! About 10 questions were unanswered. I still managed to keep my composure and finished the remaining parts of the test - Math, Science, and Grammar. I scored well in all the areas and low in the Reading - though I still passed the test! Because I knew I could score higher, I re-scheduled the test and took again two weeks later. I scored really well.
I went on the internet and YouTube and watched videos on Mitosis and Meiosis and other pertinent science topics. Having Chemistry and A/P classes taken will definitely help you. The Science portion of the test is the hardest (kinda like a crap shoot) though I scored 79% in this area which from what I hear is pretty good. I was suprised as it was a bit hard. Know the periodic elements and all the entire content in the "Science" section of the ATI book a bit beyond what is explained in the manual. Most of the Science questions are from the ATI manual, however, asked in such a way, where you have to use critical thinking to eliminate the wrong answers and choose the correct one! The Math, Grammar and Reading portion of the exam is very similar to the ATI study manual and seemed straightforward. I did have a few Q's in the Math section on geometry and pythagorean theorem. Gauge your readiness by taking the ATI on-line version practice tests (forms A and B). My actual TEAS scores were about 10 points higher than the practice tests (practice tests slightly harder in some areas). These are pretty similar to the actual exam. Schedule your exam at a place you think is quiet and reputable. Take deep breaths and say positive affirmations before starting the exam "I can do this" etc. Watch your time while taking the test - if you don't know an answer you may skip it and come back. However, allow yourself time to go back to these unanswered questions. Make very logical guesses if you're unsure of the answer - don't leave any unanswered questions.
Good luck to those taking the TEAS.