How do I cook beans without having too many that are split?
Beans split because the seed coat isn't soft enough when the interior of the bean rehydrates.

Two factors that can help ease this problem:  


soak your beans to make sure the seed coat is well rehydrated when the bean interior cooks.  
This is the big one- heavily salt your soaking water. The salt ions will replace calcium in the bean skins and soften them. You will have magically whole beans.


Refer to the Food Lab article on chili which contains this image: