The great thing about the IR section, is that you will already be studying for it when you study for the quant and verbal sections, so it should not require a lot of outside work. The skills you will learn from your Quant and Verbal prep will help you immensely, but I would also recommend getting an idea of how to use them in different ways for this section. MGMAT has a free course that is a great resource for someone looking to do this.
Furthermore, If you are aiming for a top score and building your mental endurance then you will naturally practice with these sections several times when you are going through your full length CATs. Make sure to go over the IR questions you got wrong so you can learn from your mistakes.
The IR section is quite a lot of information packed into a short period of time. Unlike the quant and verbal sections of the test, leaving a question blank and an incorrect answer have the same penalties, so there is no need to rush through it to make sure everything is answered. With that being said, there are still a lot of questions to answer, so strategically skipping questions might not be a bad option.
You can either choose to go through the section and answer each question to the best of your ability or you could skip some questions. To figure out which questions to skip, you should take a few practice IR sections and figure out what question types take you the longest and what you types you get incorrect most often (for me, it was multi-source reasoning). Then when you see those questions on test day, just guess and move on, then you have more time to work on questions you are more likely to answer correctly.
