There is no extra work involved, although the work in honors classes may be slightly different than that covered in a larger class setting. Because class settings are smaller, you'll have more opportunities for discussion with your teacher.
With the individualized attention, you are able to learn more, and work with the teacher to keep your assignments and college GPA strong.
As with any course, if you do poorly, it will hurt your GPA. However, if you do well, your effort will be noticed and an HA or HB will look better than simply an A or B.
Taking an honors class will give you an opportunity to work with professors in an intimate class room setting and will better prepare you for what you will face when you transfer to a four-year college, or transition into your desired career field.
Additional benefits include: