If you find yourself being bullied at school, one of the best things to do is contact any relevant authorities like teachers and guidance counselors and get them to take action as soon as possible, keeping evidence of the bullying. Several other coping tactics exist, depending on what is occurring.
Bullies ultimately want a reaction from you, whether it's fear or anger. As anger-inducing or hurtful as they may be, try to ignore harmful words or rumors. Words have only as much power over you as you give them.
Bullies also usually move as groups, so if you have friends, try to be with them whenever the bullies are around to add a sense of safety in numbers. Try to plan alternate, well-traveled routes to getting between classes if the bully regularly picks on you en route.
If the bullying continues or threatens to escalate into physical violence, tell an authority figure the first chance you get. Avoid fighting if at all possible; not only could a group of bullies seriously injure you, but you could end up in trouble with administrators or even legal trouble. Only use the amount of force necessary to defend yourself; take martial arts classes if they are available because they can teach you skills and increase self-confidence.