I have taken the Praxis but it was for Elementary K-5 (0014). I was really nervous about taking the exam, but it turns out that it wasn't too bad. The passing score for the Elementary K-5 is 141 and I received a 153.
The only thing I can suggest is make sure you have a good night's rest the night before, try to avoid caffeine for a few days before, have a good breakfast the morning of the exam and relax. Studying for it before hand will make you more nervous. If you want to get an idea of how you will do, you can take the practice exam that is offered on the www.ets.org
website for your specific content area.
At any rate good luck!