Go to one of the many social networks online that offer to teach English in exchange for learning your language. Websites like iTalki, Livemocha, and Lang-8 are all social networks that provide peer-to-peer teaching for free. Register with those sites and enter chats to improve your understanding of English.
Download Skype. Many of the social networks suggest using Skype to improve your English. You will talk and listen to other people in English. Try to do this every day for at least 30 minutes. It will help your accent and your understanding of English.
Watch English-speaking TV on the Internet. It is one of the easiest ways to improve your English, without you having to do anything. You will start to understand the pattern of English speech and the sounds will become more normal to you.
Take tests and challenges from English teaching sites, like learn-english-online.org. It will help you start thinking in English.
Download lesson plans for the English teaching sites to your MP3 player so that you can listen and practice when you are away from your computer.