Assuming you are referring to Rails specifically, not just Ruby. As an aside, get the book Agile Web Development with Rails. (Use the Google).
ActiveRecord’s finders either return an array:
@users = User.find(:all, :conditions => [‘name = ?’, ‘scott’])
or one object
@user = User.find
(1) # gets the user with an ID of one.
to iterate, you can use .each:
@users.each do |user|