Novice developers should not be writing drivers in any language. If you don't have a C background, you're not going to be able to contribute much code to any OS. Besides config files and scripts, NetBSD is nearly 100% C.
If you really want to get into OS programming, I recommend you start with "Computer Architecture" by Hennessy & Patterson along with a course in C programming.
If you really want to get into OS programming, I recommend you start with "Computer Architecture" by Hennessy & Patterson along with a course in C programming.
[1] http://www.ohloh.net/p/netbsd