There is no substitute for hard work and dedication to achieve your goal..it's a universal law, isn't it?
Anyways let us come to a point..if you will Google it will pop up lots many websites to come extend some sites you will find useful just go through it whatever catches your interest. But at the end of the day only reading, reading and reading will help you to improve your English dramatically...and after a certain period of time you yourself will notice it. I can jot down lots of website; chances are there you could have come across them. But you should take a path that will definitely lead you to the success, although a long and at times you have to motivate yourself. But success is guaranteed. So there is three golden rules: reading, reading and reading