How can I start in selenium automation testing ?

You can start selenium automation testing by taking selenium testing course online. You will learn from the basics and go to advance. Definitely you will become expert in few days.

At first you need to perfrom the Selenium IDE (Record & Play pack). 

Then you can move to selenium web driver. 

For selenium web driver you

1.need to update java

2.Download the Neone Latest bversion

3.Download Web Drivers form Selenium.org (Chrome, Opera , Ex...)

4. Download the Jar Files 

Selenium is trending these days as it is open source and easy to use. It enables user to write tests in multiple languages like Java,C#,Ruby,Python.

To start with, install the selenium IDE from http://www.seleniumhq.org/projects/ide/.

Depending on the browser you can install the IDE. Open the application and you can record the tests using IDE. Once you get familiar with IDE, you can develop your framework using Java-Eclipse or Visual studio-C# and write your own scripts using different Selenium Jar files.

Happy Testing!!

Please start with http://www.seleniumhq.org/. You will have all the necessary downloads and documentations on this site. Please go through it.

Install Selenium IDE from https://addons.mozilla.org/en-US/firefox/addon/selenium-ide/. This is a firefox plugin. Download it record all the events for all the actions you do in a webbrowser. You will get a series of events on the test case area of the ide. If you know coding on JAVA C#, Python or Ruby , it would be an added advantage. I recommend learning any one of them. You can export the recorded testcases in any of above languages.