There are many things you can do to help out with the Mozilla project in the QA department, and all of them don't require being able to code. A few of them don't even require knowing any HTML or other web technologies. If you are interested in helping us out with testing and other QA activities, you should first see quality.mozilla.org.
The more effectively a bug is reported, the more likely that an engineer will actually fix it. By following these guidelines, you can help ensure that your bugs stay at the top of the Mozilla engineers' heap, and get fixed.