Where is the fountain of knowledge for learning about CNC setups / understanding them

[Palletlad]

Hi all I have set up my CNC 6040 machine now and have an issue with the motors jamming whilst manually moving them (jams and makes a high pitched noise)
To my understanding this could be my setup of the motors but when I initially got my machine moving yesterday I moved all the motors fine with no issue so not 100% sure.

At the moment I am just copying what others are telling me to put in mach3 settings but I would like to know what I am inputting and why so that I can better understand my machine.
Is there anywhere particular I can look up for research material or download a book etc. and or is there sites to avoid as known for giving incorrect information?

If you are interested my settings on the motors are on the attachment, I am not sure what else you require other than I am using 220v and all three motors have jammed.
PS the temperature in my garage has dropped to 3 degrees I do not know if this makes any difference in the structure/performance of the machine itself.

Kind Regards Graham