Tool length offset and work offsets

Hi,

I am new to machining and I have recently built a cnc machine with linuxcnc and probe basic. 

I am just wondering if anyone can explain to me how to set the tool lengths and work offsets.

Much appriciated. 

For general information on work offsets see:
linuxcnc.org/docs/2.9/html/gcode/coordinates.html

For general information on tool offset see:
linuxcnc.org/docs/2.9/html/gcode/tool-compensation.html

As for specific information on how things work in 'ProbeBasic' I'm not sure where to look as that is an external project but maybe here would be a good place to start:
kcjengr.github.io/probe_basic/