If you have any specific questions on CNC in general, or the Haas control, feel free to PM me, I'm quite familiar with both.
As for general learning, it just so happens that 1306 has been running some summer classes for our students, and I taught at crash course in CNC. All my powerpoints, and my speakers notes (basically a script) can be found towards the right side of the google doc
here. Make sure to read those speaker's notes under each slide, the slides won't make much sense without them.
This class was tailored towards our machine in particular, which is a lower-end machine with some weird quirks, so you can ignore those parts of the presentation.