Reading section is although common in both the exams, there is certain amount of difference on how both of them, test your skill.
TOEFL-: There are three to five sections of twenty minutes each. The reading material is academic in nature. The questions asked are of multiple choices. The reading passage deals with topics you would study in your initial years in university. For example-: natural sciences, social sciences, business or arts. You need not to know about these topics. What TOEFL checks is, whether you can understand a completely different topic or not. You are required to attempt all the sections of it. Although there might be a chance that you are not graded on one of them. They could be used for experimental reasons.
IELTS-: The reading sections consist of 40 questions. There will be variety of questions asked in order to check your various reading skills like skimming, reading for detail, recognizing writers’ opinions, attitude etc.
There are two versions to it-:
IELTS Academic-: It includes three long texts. They could range from descriptive to factual to discursive or analytical. The texts are usually taken from books, magazines or journals. These are selected for non-specialist audience but are perfect for those trying to enter into a university.
IELTS General-: The reading material in this module includes general materials available. For example, magazines, advertisements, newspapers, handbooks, guidelines etc. You would be usually reading extracts of these. They would be what you are likely to encounter in your daily life.
No matter what test you take, to get high marks in reading section, all you need to do is read, read a lot, enjoy it and read more.