Newbie looking for beginner's software

Hi, new to the group and also CNC machining. I won an auction on Ebay
for a Sherline mill with a MaxNC kit. Now the problem is learning to
program the thing.

I am experienced in manual machining and AutoCad. I was just wondering
if there was a easy low cost program that would be best for a beginner?

Is there any books in paticular that are good for a newb? Thanks

Gus H.