Your question is a bit vague, @jahidhossain00. It sounds as if you’re asking for somebody to teach you all about the subject, which of course isn’t the purpose of a forum.
Did you start with Facebook’s own advice?
There’s plenty of advice in there. If you’ve already followed that, then please explain in more detail what additional information you’re looking for.
You should also take a look around the Marketing and Social Media categories, as we have had several threads discussing this issue. For example: Facebook Marketing Strategies