Machine knitter in distress

I have put the three images in this post as links so you can see them a a better size - I'd have had to shrink them for blogger.

Photo 1 - Initial cause of distress is that I can't get the machine to cast on. I have tried fiddling with the various settings but it just keeps missing loops. What am I doing wrong?

Photo 2 - These are the settings on the carriage. Can't find anywhere that tells me what the letters mean on the dial top right or whether the slider on the right should be on N or H. Also not sure whether the wheels at the bottom of the carriage should be engaged or not. Don't worry about the wool position - I was just moving it out the way to take the pic.

Photo 3 - I don't know what these two sliders are for either.

As you may have gathered I got the machine second hand and without a manual. I have downloaded the free brother 851 manual from online but despite reading and re-reading can't see where I'm going wrong. It is the casting on (or lack of) that is the main issue, obviously! So frustrating as the first time I got it out it worked fine except the knitting got stuck on the sinker posts. That'll no doubt be my next question!

If anyone can help me please email littlelixie@hotmail.com THANKS x