There are some ways to improve your English, but I think the most important thing is to make English all around you. Here is some advice for you.
Listen to the radio in English. If there are no English radio stations where you live, listen to one on the Internet.
Watch TV and movies in English. If there are English channels on your TV, watch them. If there are no English channels, you can buy some DVDs of English movies.
Speak English to your friends. You can make friends with someone who is good at English and speak English with him or her as much as possible. You'd better make friends with people whose native language is English. Ask your friends to correct your mistakes when needed.
Study or travel to an English-speaking country. Of course the best way to improve your English is to live in English environments. You will find yourself surrounded with the language everywhere. It can be a more difficult and expensive choice, but you may find it to be a very valuable and helpful experience.