I used the Mcgraw-hill e-guide that someone posted for downloading on here. The reading, however, was NOTHING like in the guide. I'm not sure what the ATI testing guide looks like to be honest. Here is what you should study for each section (IMO)
Reading-- It's very short paragraphs and some medicinal labels and whatnot that you have to read and gather the appropriate information from. For example..one of the questions was about a label on a medicine bottle and asked "which statement below from a patient would cause concern if they are taking this medication?" and then there are four choices to choose from.. There were a few where you have to follow directions and draw little diagrams and then choose which on looks like yours, etc. It's very much not like any reading comprehension test I've ever taken.. The answers are all RIGHT there.. Just read them all carefully and you will do fine.
Science-- It's similar to the study guide I used; however, there are many questions not related to health topics. There were questions about rock formations, cloud formations, tectonic plates, etc. It's basic stuff for the most part. A thorough review of basic biology, chemistry, and beginner physics will help.
Math-- It's just like any other math test I would say. It is mainly geometry and algebra. You will need to know the formulas for area and circumference of circles by heart.. which shouldn't be difficult.
English-- This is all about sentence structure, grammar
, vocabulary, and some other minor topics. I would review the basic rules for punctuation (like where commas go in sentences including inside or outside of quotation marks). I was nervous about the vocabulary section, but almost all of them had really good context clues to help you get your answers.
I hope this helps! Good luck!!