Documentation on Device Drivers?

[Mech. Eng. Robotics Group]

I have been trying (unsuccessfully) to track down some documentation on
writing device drivers for System V.  Does such a thing exist?

Are there any good books on the subject?
Anyone have any documentation of their own that they would like to share with
me?
Are there man pages floating around somewhere out there for kernel routines?
Are there other sources of information?

Any input would be greatly appreciated.