To use a functional jQuery script into Blogspot blog you have to linked jQuery source code from any realible and trusted host into your Blogspot Blogger Template Editor, here we use jQuery hosted in Google server.

How to add jQuery into Blogspot Blogger Template

• Login to your Blogger account
• Before making some modification you can back up the template first.
• Then open Blogger HTML Template Editor
• You have to search for a line of code in the template, here is how to search the code and enter </body> in the search box then press enter.
• And right above it enter this tag:
  

  <script src='http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js'/>

• Click on the orange Save Template button.

The example use jQuery version 1.11.2, you can use your own version, find it here https://developers.google.com/speed/libraries/devguide#jquery More..