Preparation for exams should begin on the very first day, and continue up until the day before an exam (but NOT the day of).
Lab exams will consist of stations set up in the lab, where you'll be required to identify structures and give their functions, describe their locations, etc. Lecture exams may consist of a combination of multiple choice, fill-in-the-blank, diagramming, and essay questions.
Make sure your review this handout...
... as well as these resources for writing in-class essays:
Finally, I've prepared a series of Practice Exam Questions and tips to give you an idea of the kinds of questions you'll be expected to answer. Please note that the sample Venn diagram is not meant to be complete, but rather to model one method of brainstorming for an essay.
One final note: It's a great idea to write mock exam questions and exchange them with your classmates! I can't grade your practice exams like a real exam. However, I'm always available during student office hours to help you understand the material and answer specific questions.