How can I use a gryoscopic sensor with Arduino?

Hello, I am a high school student and my high school is having a robot competition. There are many events that we compete in and one of them is for speed. In class we saw the previous years entries and one of the most important factors for this event was the ability to in a straight line. I am familiar with gyroscopes and how they work and was wondering if I could use a gyroscopic sensor to keep my robot from zigzagging around. I am not very experienced in Arduino, however, I only know a bit on how to code the servos, touch sensors and other things. If anyone could advise me on how to use a gyroscopic sensor or which type/model to buy that would be great. Additionally if you have any ideas on what could make my robot go faster that would be amazing(right now I'm thinking about a balsa wood constructed chassis and 3D printed plastic wheels). Thanks!

Additional Info: Servos that we have to use for propulsion: http://www.amazon.com/Micro-Servo-Arduino-23-12-5/dp/B006YX11AA The robot cannot be more than 8in x 8in x 8in (20.32 cm) and weigh more than 4lbs(1.81437kg)