[impendia]

Great answer, and let me add one thing, if OP has the opportunity and desire to prepare in advance.

Usually the hardest thing about calculus is the precalculus. All sorts of algebra and trigonometry problems appear in the course of calculus problems, and if you can solve them reliably and quickly then you can concentrate on the calculus.

I'd recommend buying any precalculus book -- look for used copies of edition n-1 on Amazon, where n is the latest version - and doing the hardest exercises. These will be starred, and/or at the very end of the section. A great way to build up your chops.