Need CAD/CAM/ software recommendations

I want to learn a bit more about CNC machining. I'd like to pick up a
controller board from HobbyCNC and some steppers and build a 3-axis
training setup. The mechanical portion and conventional machining is
the easy part for me. What I need help with is finding the software
to help with the design and coding, also good book recommendations on
G-coding. I was wondering is what folks would recommend from
personal experience in the way of easy to learn basic CAD/CAM &
control software, preferably shareware to start with. Thanks.

Chuck