What should you do first?PREDICTING!!!
Have a look at the title and any pictures that accompany the text, also count the paragraphs. The title normally tells you the topic of the text, pictures give a lot of information which is not in English!!!! Each paragraphs brings up a new idea on the main topic. Now that you have some information, think about what ideas will come up and better than this, what words, expressions, even grammar and textual features...
What should you do next? UNDERSTANDING!!!
Read the text one paragraph by one and try to understand the main idea of each one and how it relates to the main topic (understanding a text has a lot to do with understanding what it is talking about, that is the world to which it makes reference). Don't worry about the words you don't understand, try to figure them out; two good ways are: trying to relate it to a word you know (whether in English or Spanish) or trying to fill the meaning gap - this can be fun, teachers should practise this in their classes more often. It is also important to take into account textual references such as those of personal pronouns and others.
What should you then? GET DOWN TO WORK!!!
Now it is time to read the exercise you have to do in order to show that you have understood. What do you have to do? There are different types of exercises which go from the fill-in gaps to the question answering or from multiple choice questions to finding synomyms or opposites... Depending on your level, your teacher will ask you to do different tasks. Many teachers ask students to answer questions, so it is important that you know your wh-words!!! Go back to the text and look for the information you need.
You can get deeper information on how to develop reading skills in your own language and others if you go to How to improve reading comprension. You have many corrected instances at English for Everyone.
Will you follow these tips?