Find:

• The Ruby API => http://www.ruby-doc.org/core-1.8.7/index.html
• The free online version of Programming Ruby: The Pragmatic Programmer's Guide => http://ruby-doc.org/docs/ProgrammingRuby/
• A method that substitutes part of a string => str.sub(pattern, replacement) also str.sub!,str.gsub,str.gsub!
• Information about Ruby's regular expressions => Regexp
• Information about Ruby ranges => Range (1..2) vs (1...2) (eg. [1,2] vs [1])

Do:

• Print the string "Hello, world." => puts "Hello, world."
• For the string "Hello, Ruby." find the index of the word "Ruby." => "Hello, Ruby.".index("Ruby.")
• Print your name ten times => (1..10).each{puts "Andreas"}
• Print the string "This is sentence number 1." where the number 1 changes from 1 to 10 => (1..10).each{|i| puts "This is sentenc number #{i}"}
• Run a Ruby program from a file => ruby file.rb
• Bonus problem: if you're feeling the need for a little more, write a program that picks a random number. Let a player guess the number, telling the player whether the guess is too low or too high.