Crawling for emails on websites given by Google API
As @tokland pointed out, the major thing that jumps out when reading your code is the indentation problems. In most Ruby code you see, the standard indentation is 2 spaces. It looks like you are using hard-tabs, which are generally a bad idea. You should explore the settings of your text editor -- most have an option to insert spaces instead of tabs when you press the "tab" key. Here is your code would look like if indented properly:

require "nokogiri"
require "json"
require 'mechanize'
require 'anemone'
require "typhoeus"
require "timeout"

class String
  def to_bool()
    return true if self == "true"
    return false if self == "false"
    return nil
  end
end

class Query
  def initialize(keyword)
    10.times do |n|
      num = (n * 10 + 1).to_s
      p num
      req = Typhoeus::Request.new("https://www.googleapis.com/customsearch/v1?key=[my_key]&amp;cx=018020274830505137072:utuofm0ugh0&amp;q=" + keyword + "&amp;start=" + num, followlocation: true)
      res = req.run
      File.open("file.json","w") do |file|
        file.write(res.body)
      end
      continue = "true"
      fs = File.read("file.json");
      string = JSON.parse(fs);
      string["items"].each do |item|
        p continue.to_s + "&lt;- item"
        begin 
          Anemone.crawl("http://" + item["displayLink"] + "/") do |anemone|
            anemone.on_every_page do |page|                           
              if continue.chomp.to_bool == false
                raise "no more please"
              end
              request = Typhoeus::Request.new(page.url, followlocation: true)
              response = request.run
              email = /[-0-9a-zA-Z.+_]+@[-0-9a-zA-Z.+_]+\.[a-zA-Z]{2,4}/.match(response.body)
              if email.nil?
              else
                p email
                begin
                  continue = Timeout::timeout(2) do
                    p "insert now false/nothing"
                    gets
                  end
                rescue Timeout::Error
                  continue = "true"
                end
              end                 
            end                   
          end                 
        rescue Exception =&gt; e
          p e
          continue = "true"
          next                  
        end
        p "---------------------------------------------------------"
      end
      p "new request"
    end
  end
end

qs = Query.new("texas+web+development")


For your to_bool() function, this might be a little nitpicky, but I would rewrite it as a case statement like this:

class String
  def to_bool()
    case self
      when "true"; true
      when "false"; false
      else; nil
    end
  end
end


The URL you're passing to Typhoeus::Request.new is ratehr long. You might consider doing something like this to shorten your line lengths a little:

base_url = "https://www.googleapis.com/customsearch/v1?key=[my_key]&amp;cx=018020274830505137072:utuofm0ugh0&amp;q="
req_url = base_url + keyword + "&amp;start=" + num
req = Typhoeus::Request.new(req_url, followlocation: true)


Or, if you want to be really diligent about not having long lines, you could do this:

base_url = "https://www.googleapis.com/customsearch/v1"
key = "[my_key]"
cx = "018020274830505137072:utuofm0ugh0"
req_url = "#{base_url}?key=#{key}&amp;cx=#{cx}&amp;q=#{keyword}&amp;start=#{num}"


You have a part of your code that goes if email.nil? (nothing) else (something). A better way to put this would be: 

unless email.nil?
  p email
  # etc.


As a general note, you could make your code more concise by using less "intermediate" or "throw-away" variables. Take advantage of Ruby's method chaining and try condensing your code like this:

...

# No need to define a variable res; req.run is short enough
req = Typhoeus::Request.new(req_url, followlocation: true)
File.open("file.json", "w") do |file|
  file.write(req.run.body)
end

...

# You can get rid of the fs and string variables and do this: 
JSON.parse(File.read("file.json"))["items"].each do |item|
  p continue.to_s + "&lt;- item"
  # etc.

...

# You could change the name of the variable from request to req, 
# for consistency -- you named another Typhoeus request "req"
# earlier in the code, and it doesn't look like you still need
# that variable, so there's no harm in re-using the name "req."

# Notice how you can eliminate the need for the variables "response"
# "email" like this:
req = Typhoeus::Request.new(page.url, followlocation: true)
email_pattern = /[-0-9a-zA-Z.+_]+@[-0-9a-zA-Z.+_]+\.[a-zA-Z]{2,4}/
unless email_pattern.match(req.run.body).nil?
  # etc.


You might consider changing if continue.chomp.to_bool == false to unless continue.chomp.to_bool, or even if continue.chomp == "false". In fact, I think I like the last way the best -- you could totally do away with monkey-patching a String#to_bool method and just compare continue.chomp to "true" or "false". It's your call, of course. :)

Lastly, this is just my 2 cents, but I think you could simplify the way you're using continue. If I'm understanding correctly, it starts as "true" and you want the program to keep running unless the user types "false" when prompted. I would consider doing away with your String#to_bool method and just comparing whether or not continue.chomp.downcase equals "stop", "exit" or "quit". You could do something like this:

stop_words = ["stop", "exit", "quit"]
continue = ""

...

if stop_words.include? continue.chomp.downcase
  raise "no more please"
end


This would save you from having to keep doing continue = "true" to make sure the program doesn't stop. As long as the value of continue.chomp.downcase is not one of the stop words, the program will keep running.

I admit, though, that I don't really understand the use of continue in p continue.to_s + "&lt;- item", so maybe there is something I'm missing.

Anyway, hope this helps!