Respect is a simple meter indicated in the top-right corner of the screen, a purple bar under your yellow stamina meter. In order to attempt the storyline missions, you need to have achieved a certain level of respect with your gang.
If you played the original, most of this should just be a refresher course.
While the general idea of Saints Row 2 is not hard for anyone to grasp-especially not for those who have played Grand Theft Auto III or IV-SR2 does have its own unique aspects that might be new to you.
