How can I keep a cheesecake from cracking?
To make a good baked cheesecake, I was taught the following, and it has ALWAYS worked:


Start with room temperature ingredients.
DO NOT over-mix. This is a significant cause of cracking, as the incorporated air tends to souffle.
When baking, always bake in a bain-marie (put your cake into a water bath for insulation).
Bake half an hour at 300° F / 150° C.  Then, turn off the oven, open the oven door, and rest for 30 minutes.  Then, close the oven and bake 30 to 40 minutes more at 300° F / 150° C.


My first pastry chef taught me this, and it always works.

Also, over-baking will definitely lead to cracking (due to the loss of moisture), and, as stated, over-mixing will as well.