What do i need to have to be ready for the ACT?

I'll put my highest scores as of yet in parentheses behind the advice so you can tell I know what I am talking about (or don't).
Math: know how to work with functions including composition of functions which occasionally comes up. Also exponent rules are important, word problems are there, and of course isolating variables :) I don't know much about the trig though, I still haven't taken it, so I just make my best guesses on those. (30)

Science: Practice interpreting graphs and data tables. That is a HUGE part of the science. There has also been opposing scientific viewpoints that you have to answer questions on. (31)

English: It is usually the shortest answer that makes sense. You REALLY need to know your grammar, sentence structure, what makes it a good sentence instead of a fragment or run-on, the difference between words that sound the same (whose, who's, etc),choosing the right tense, whether to change or omit a portion, paragraph placement, and comma rules. I was looking in a practice ACT book for these, and these cover majority of the types of questions for English (35 which is my best)

Reading: Try to improve speed reading while still being able to comprehend what you are reading. That will come in useful. If you run short on time (5 min )and have say, 1 passage left, read the first and last paragraphs quickly for the main ideas, and skim the rest for answers. (33)

Good Luck~!