Initial configuration & Setup motor speed

Hello everybody
Excuse my ignorance but I have a couple of doubts in the initial configuration
What values should I change for jog speed and max velocity? In hakan's video I saw that it is 720 instead of 300.
 
the pos-scale value in the hal file 4000 how is it defined?
setp cia402.0.pos-scale 4000
Thanks

the cia pos-scale is defined as increments per 1 Machine Unit.

that means: if your feedback gives 4000 increments per 1 Unit (mm or inch) this setting has to be 4000.

for the rest: read the ini section of the linuxcnc docs.

The Max Velocity slider's settings aren't completely clear in the docs.
It and the default jog speed are set in the TRAJ section of the ini file with.
MAX_VELOCITY =
and
DEFAULT_VELOCITY =
The MAX_VELOCITY sets the limit for both sliders, and the DEFAULT_VELOCITY sets the initial setting for the Jog Velocity at startup.

Beware, all of these settings are in machine units per second not mm/min. So you will need to remember to divide a mm/min setting by 60 to get the value you want.