Great content is the key. Post something interesting and relevant; ask questions and engage people into conversation. Healthy dose of humor will also help.
You should post some interesting and unique content. So that more people will get attract to your page. You can also start some contests like photo contest, in this way your fans will invite there friends to vote and your fans will increase, You can also buy fans from many sites at very cheap rates like SEOclerks, listingdock etc.