Periodic questions will be anonymously posted for web browsers. This is my first semester at ASU and I am not sure when to start worrying about finals. I would recommend now if you haven't already started. The more prepared you are for your finals the less stressed out you may be. It is important to find out the nature of each final.
Some finals are comprehensive - meaning they cover the entire course content.
Others will only cover new material presented after the last exam. Look on your syllabus or talk to your instructors to get a feel for what the final will be like. Ask about study groups or sessions that you can attend. I like to join study groups especially to prepare for finals. If there is not a study group form your own.