How to study English

First, you should know that there are lots of ways to learn a language. And over here I will share this precious information to you.

Do something to practice the four skills of any language.

Speaking skill:

Try to speak as much as you can. You can use these websites to practice your speaking skill 
www.sharedtalk.com , www.livemocha.com and also download Skype to make video calls with your language partner.

Listening skill:

Try to listen to music, and to English spoken radio http://www.bbc.co.uk/radio/player/bbc_world_service, watch the news in English language, watch movies, dramas, anime, or just talk to a native English speaker on www.sharedtalk.com , www.livemocha.com , and try to use Skype.

Reading skill: 

Read as much as you can, read books, magazines, manga, read the news in English language.

Writing skill: 

Try to write down anything that is on your mind, like writing a diary, write essays; describe what you have seen today and what has happened today.

Finally 

You should study English grammar, and if you want to learn new vocabulary you will find it in the books you read, in the movies you watch. Or when writing down an essay, you should find new words to have it better. Or when speaking, try to look up new words or those words you don't know and that you want to say.