I am thinking about migrating a Windows driver into OS X. Now I am just starting to look around to see what is available and there is a lot about objective C and cocoa. Seems th
Start here http://developer.apple.com/documentation/Darwin/Conceptual/KernelProgramming/About/About.html
Mac development is generally done using Xcode, as it handles various Mac-specific concepts like bundles and frameworks. You will most likely be working in pure C. You will not be using Cocoa for driver development, as that is an application-oriented framework.
If you're targeting Catalina or higher, you should also consider DriverKit.
First, C++ works just fine, although Objective C is not all that hard to learn. If you have a background in Windows drivers you know some of the essentials- memory management is critical, time is critical, etc.
You will probably be using the IOKit. I suggest starting here for a good, step by step intro to getting the driver to work.
Kernel Extensions
There are a few things that don't seem to work the way they say they will, and I'm trying to figure out if it really is not possible to debug a driver on a single machine, but it's better than most Apple documentation.
The Apple Hardware & Drivers page has lots of information about Mac driver development. It should be enough to get you started. Some of the highlights:
Getting Started - A guided learning path for hardware and driver developers new to Mac OS X.
Frameworks - API references organized by framework.
USB Sample Code - Resources for developing USB devices and software to access them.
FireWire Sample Code - Resources for developing FireWire devices and software to access them.