I have tried the following steps, and it works smoothly to Setup Selenium IDE, hope this little contribution can help who want to start learning Automation Testing using Selenium. Following are the steps:
1. Go to http://seleniumhq.org/download/ and click on Download Version 1.6.0 or latest and allow the pop-up.
2. Install the Selenium IDE Add-on
3. Once the Add-on installation is successfully completed restart the browser and start using Selenium IDE which is available in Tools menu (short cut - Ctrl+Alt+S)
Note: Selenium IDE will be useful for Record and Playback only. If we want to add dynamism we need to go for Selenium Server or RC / Web Driver.