And one of the best ways to improve your spoken English is to, well, practice speaking English!
If you have access to a computer (and since you're reading this, I assume you do), sign up for Skype and then search the internet for chat rooms where you can speak. I'm sure there are even chat rooms specifically for practicing English.
Another way is to speak English in conversations with everybody you possibly can.
Just remember, Speaking English is a skill that is learned over time. And as with any skill, the only way to get better is to practice!