Don't be nervous. Although the class and simply the word, CALCULUS, may seem daunting, it's by no means impossible. I am not a math guy either but did well in both Calc I and II. The key is to attend class and if possible, visit the teacher's office hours for extra help. There he/she can give you one on one help with your specific questions (that's what worked for me). Also, you need to do practice problems until you just can't look at them anymore. Once you do that, you can be sure that you have seen everything and nothing on the test will look unfamiliar. If possible, purchase a calculus help book like the Dummies Guide or whatever. They provide extra problems in there too that you can solve and often times, they are more helpful than the textbook itself (mine was crap at explaining anything).
This might sound stupid, but another key is actually understanding what you are trying to do and to actually apply it to the problems in the specific section. Keeping in mind what you are trying to do helped me in each section of new material.
ANOTHER tip is to try and get your hands on back tests. Fortunately, my roomate took Calc II before I did so I had access to all of his back tests which REALLY helped me because the test that I took were very similar to the ones he took (calculus is calculus, you can't really change much but the numbers and how you ask the question. The material stays the same).
Also, try and do atleast an hour of calc work per day. That way, it's all fresh in your head when you go to take the test. You won't really be studying for your test, but rather reviewing for it since you kept up with it (calculus is hell if you fall behind even for just one section).
Hope this helps. I know it did for me.
G'luck
Oh, and P.S. don't listen to other people when they tell you that the course is soooo hard and how theyre failing and when they tell you that this is their 15th time taking it so good luck. Calculus II here at Temple has a 50% fail rate. Refuse to be a part of the 50% and you're golden.