Milad,

The questions you ask don't have answers.
How many lights do you need? That depends on what the end result should be.
Where should I add my lights? That depends on what the end result should be.
Etcetera etcetera, it all depends on the end result you want to achieve.

You can [url=mailto:[email protected]]send me[/url] your file, and I shall see if I can help you a bit more.

Hans