CV means Curriculum vitae which used in place of a resume in Briton.
Being that I have only a High School diploma is it even worth applying to be a tester? Would there be anyway to get a leg up on the competition, since I don't have a degree or anything? How do I go about creating a cover letter?
Experience trumps education, unfortunately you have neither which doesn't help. You may as well apply, at worst you will be rejected. At best, you will have a job.
You should be able to find a few examples of cover letters on the net. This thread may help: http://www.igda.org/Forums/showthrea...threadid=35886