If you already have a Facebook Page then,
Add some unique content, attractive images, product or services details into it.
It will be good if you can offer something as in start.
Then ask your friends to like the page, vice versa, ask your friends to ask their friends to participate in your facebook page like liking updates form you, commenting on page.
Do some forum posting wherein involve people to get into your facebook page.
Meanwhile, be active for every like, comment you receive.
Try to be interactive with all Facebook members so that they can participate well.
And obviously you can go for local ad posting.