How to do 301 redirect ?
URL redirection, also called URL forwarding, domain redirection and domain forwarding, is a technique on the World Wide Web for making a web page available under many URLs.
301 redirect is the most efficient and Search Engine Friendly method for webpage redirection. It’s easy to implement and it should preserve your search engine rankings for that particular page.Someone use this idea to get fake google PR, just say blackhat. If you have to change file names or move pages around, it’s the safest option. The code “301” is interpreted as “moved permanently”.

Here are  some easy methods to implement URL Redirection

• IIS Redirect
  In internet services manager, right click on the file or folder you wish to redirect
  Select the radio titled “a redirection to a URL”.
  Enter the redirection page
  Check “The exact url entered above” and the “A permanent redirection for this resource”
  Click on ‘Apply’
• ColdFusion Redirect
  <.cfheader statuscode=”301″ statustext=”Moved permanently”>
  <.cfheader name=”Location” value=”http://www.new-url.com“>
• PHP Redirect
  <?
  Header( “HTTP/1.1 301 Moved Permanently” );
  Header( “Location: http://www.new-url.com” );
  ?>
• ASP Redirect
  <%@ Language=VBScript %>
  <%
  Response.Status=”301 Moved Permanently”
  Response.AddHeader “Location”,”http://www.new-url.com/”
  %>
• ASP .NET Redirect
  <script runat=”server”>
  private void Page_Load(object sender, System.EventArgs e)
  {
  Response.Status = “301 Moved Permanently”;
  Response.AddHeader(“Location”,”http://www.new-url.com“);
  }
  </script>
• JSP (Java) Redirect
  <%
  response.setStatus(301);
  response.setHeader( “Location”, “http://www.new-url.com/” );
  response.setHeader( “Connection”, “close” );
  %>
• CGI PERL Redirect
  $q = new CGI;
  print $q->redirect(“http://www.new-url.com/“);
• Ruby on Rails Redirect
  def old_action
  headers[“Status”] = “301 Moved Permanently”
  redirect_to “http://www.new-url.com/”
  end
• Redirect Old domain to New domain (htaccess redirect)
  Create a .htaccess file with the below code, it will ensure that all your directories and pages of your old domain will get correctly redirected to your new domain.
  The .htaccess file needs to be placed in the root directory of your old website (i.e the same directory where your index file is placed)

Options +FollowSymLinks
RewriteEngine on
RewriteRule (.*) http://www.newdomain.com/$1 [R=301,L]

Redirect to www (htaccess redirect)
Create a .htaccess file with the below code, it will ensure that all requests coming in to domain.com will get redirected to www.domain.com
The .htaccess file needs to be placed in the root directory of your old website (i.e the same directory where your index file is placed)

Options +FollowSymlinks
RewriteEngine on
rewritecond %{http_host} ^domain.com [nc]
rewriterule ^(.*)$ http://www.domain.com/$1 [r=301,nc]

How to Redirect HTML
Please refer to section titled ‘How to Redirect with htaccess’, if your site is hosted on a Linux Server and ‘IIS Redirect’, if your site is hosted on a Windows Server.

You can Test your redirection with Search Engine Friendly Redirect Checker