A large portion of every TAs weekly hours are spent grading. Indeed for most graduate classes, the TAs role is purely that of a grader and consultant, with virtually no classroom responsibilities. Prompt feedback is of tremendous importance. You know when the due dates will be, so schedule your grading hours to minimize response time. Making solutions available is an excellent idea. It allows you to minimize comments on individual assignments and preemptively answers many questions about problems or grading. Posting your grading criteria is a good idea for the same reason.