Visit the Voice of America Special English website or the BBC's Learning English site. They contain audio versions and written transcripts of news stories. Stories are read slowly and clearly so English learners can understand them. Listen to the news on a regular basis. Avoid reading transcripts of the story until you have listened to it at least once. They also contain English lessons and activities students can use to improve their English skills.
Many free English lesson videos are available on the Internet. Some include ESL Video and ESL Media Lab. These lessons can help you master pronunciation of difficult words, learn new vocabulary and grammar points and to improve your listening comprehension in English. Watch a lesson a day, and practice its contents regularly to improve your English. Watch the speakers' mouths in the video for help with pronunciation of difficult words.
Although grammar is definitely not many people's idea of fun, learning it online can at least be interesting with online grammar quizzes to test your knowledge. Take these quizzes after you have read through a grammar lesson. They will help you see if you have truly understood the lesson. You can retake them as many times as necessary. They are a learning tool to help you master putting sentences together in English correctly. Some can be found at A4ESL.org. Many ESL grammar sites also have quizzes, such as EnglishClub.com.
Interactive games are another way to improve your English online. You will learn new vocabulary and grammar points in the games. Most games are geared toward children, but they are a useful tool for adults learning English as well. A good list of ESL games and websites can be found on the Rong-Chang ESL website. Whether your interest is in building your vocabulary, spelling or grammar, this site has links to plenty of online ESL games focused on what you want to learn.
Another option is to hire an online tutor. You can take a group or individual course. Your class will require you to have a set of headphones and a good Internet connection. You will be able to see your teacher as she will likely use a webcam, so you can see her facial expressions and how she forms words. Find ESL teachers on ESL Teachers Board under "Find Private Tutors" under the heading "For ESL Students" on the site's home page.