I started out learning on my own how to hand knit. Soon after, I started to design my own kitting patterns. I wanted to know more, and decided to buy a knitting machine. But as those who have had the experience of buying a machine, taking it home and trying it out, it's not nearly as easy as it looks. There is not much material written on the subject of machine knitting. It sort of had its heyday back in the 80's with house wives trying it out for fun, so not much is available in the professional sense.
But today, there is a revitalized interested in knitwear design using a domestic machine. While some design schools in the Europe and US offer courses in knitwear design, many of these courses are attached to a full degree study that many of us, already design graduates, have not the time to do a degree all over again to train in knitwear. Some of us designers get jobs in knitwear design, but never even touched a machine before!
If you are student or professional looking for training, then please visit these blog posts on how and where to get training. Plus resources on machine knitting.