GMAT is a well known exam and an important exam that many students take up in order to get admission to good colleges. In fact, may students all over the world write the GMAT exam. And so naturally, it is a competitive exam and cracking it is not easy. That is why when you are going to write the GMAT exam, it is better you go for gmat prep classes. This way, you will know about the syllabus, the question nature and you will be able to practice more.
It is preferable to go for coaching and thus get live interaction with teachers and instructors in the classroom. But the thing is that many people who are taking GMAT exams are working people and they do not have enough time to go for classes.But there are many online GMAT prep classes like Knewton.com. Here you will get all the practice questions online, you will get experts and instructors who will help you anytime and even live video classes. I am sure this will be useful for you.