You can find some exemplars of good work from previous semesters here and here. You can also see a comparison of good answers with the textbook sidebar definitions, if you’re thinking of memorizing those short definitions (hint: it’s not a good idea!)
I grade the individual questions on a 4-point scale: 4=A, 3=B, etc. I then total those up and, taking the highest grade in the class as 100%, convert them back to a 4-point scale letter grade with pluses and minuses. I record that grade (on a hundred point scale, so F is still worth more than zero) as your grade on the test.