[nobozo]

The first thing to do is to always be listening to people speaking English. Try to be aware of how they pronounce things and compare them to how you do it. Be aware of little things like verb conjugations. People will still understand you if you do it wrong but you'll definitely stand out as a foreigner. Also, don't talk too fast.

In your case this won't work, but try to stay away from other speakers of your native language. I see students at UC Berkeley who end up getting roommates from their same country. This is a very bad idea because they won't be forced to adapt their brain to the new language. I always found that having a girlfriend who speaks the language I'm trying to learn was a good idea.

Reading books will help your vocabulary but it probably won't help your understanding of spoken language. What I did when I was living in a foreign country trying to learn the language was to watch children's TV shows. Once I was able to speak and understand at a 5 year old's level I felt like I was ready to expand my horizons.