The book expects that you're already experienced at programming, and that you can write simple programs in Ruby.
If you're just getting your feet wet in programming, this is a very good book: http://www.pragprog.com/titles/ltp2/learn-to-program-2nd-edition.
Paolo Perrotta, Europe
Author of Metaprogramming Ruby
http://www.pragprog.com/titles/ppmetr/metaprogramming-ruby