Improved range of motion, better flexibility, which helps prevent injuries, and helps to improve your circulation. So why wouldn’t you stretch?.
Remember to save static stretches for the end of your session. Ideally, stretch the major muscle groups after exercise, then recover from the session (refuel!) shower, then spend a good half an hour stretching. It helps you to relax after a hard session as well.
The dynamic stretches should be incorporated into your warm up. For examples of both static and dynamic stretches, have a look at the attachments.