How do I use (n)curses in Ruby?
You might be able to get some implementation ideas from the Ruby/ProgressBar library, which generates text progress bars. I stumbled across it a couple of months back but haven't made any use of it.
Very late answer and sorry for self promotion, but I created library to show progress in terminal.
Personally I think curses is overkill in this case. While the curses lib is nice (and I frequently use it myself) it's a PITA to relearn every time I haven't needed it for 12 months which has to be the sign of a bad interface design.
If for some reason you can't get on with the progress bar lib Joey suggested roll your own and release it under a pretty free licence for instant kudos :)
On windows, curses works out of the box, ncurses doesn't, and for a progress bar curses should be sufficient. So, use curses instead of ncurses.
Also, both curses and ncurses are wafer-thin wrappers around the c library - that means you don't really need Ruby-specific tutorials.
However, on the site for the PickAxe you can download all the code examples for the book. The file "ex1423.rb" contains a curses demo which plays Pong - that should give you plenty of material to get you going.