Dear Ramesh,
I think you have already made first step. And success is certain for you.
It would be appropriate for you to listen some English News Channels so as your Listening skill, Understanding Ability, accent (to certain extent) that would help.
For Vocabulary built, you need to go through some simple text to start with "Chandamama", "Twinkle", Malayala Manorama coming out with a Book called "Tell Me Why?" would certainly help you out.
With that base of vocabulary built, slowly but steadily you can go and converse with people and/or write to them.
In that time only, I would suggest to go for some English Communication classes, before that if you go it would be certainly eroding your hard-earned resources, i.e., money!!
Jaikumar Ranganathan