<p>The ACT is different in that there is a science section. I would HIGHLY recommend you study the science section. Other than that, it’s english, math, reading, and science. There is an optional essay too, called the writing portion. I would take that, too. The difference between the SAT essay and the ACT essay is that the ACT essay gears its focus towards high schoolers and issues with high school. The SAT one is much more broad, and, I feel is better. So to study, definitely use the red official ACT prep book and if you are one of those people who like harder prep to get you ready for easy stuff go with Barrons. The next ACT is in February, if you check their website. I would take it then because then you have about a month and a half to keep drilling and studying. If you want more time, you can take it in the spring. Good luck and I hope I helped!</p>