Sign into your facebook account and click on ads. The steps listed will guide you through the process. You may also want to do a Google search and look into optimizing your ads so that the audience you wish to reach is best targeted. I also suggest that you read the information facebook provides regarding their ad. program. Open a Facebook business account. It has some limitations that friends pages don't have but if you have a brand then you should market the brand more than yourself.
I would like to add that advertising on FB takes time. You have to be patient. So set your budgets and advertising plans with that in mind. Facebook advertising is still a relatively new offering and marketers are just beginning to understand how to use these advertisements most effectively.