Since Facebook has millions upon millions of registered users that are logging on at practically any time on any given day or night, this is one social media site where you will indeed want to do some serious advertising. Facebook's advertising platform is a tool you will want to have that allows you to place small advertisements on the right-hand side of Facebook's pages and profiles. Some would argue that these are not nearly as effective as using something like Google Adwords' campaigns but it is really not the same type of medium and at least for now you will not find Adwords in Facebook.
If you are going to be doing advertising on Facebook you will want to be focused on targeting just who will be seeing your ads. Facebook allows you to target using quite a number of variables such as targeting by age, gender, geography, keywords, level of education, relationship status and even someone's place of work. One key thing to remember is to increase your keywords to the place it needs to be at to successfully reach a large enough audience to reach your advertising goals.
Once you have your target audience pretty well narrowed down, you need to decide where to have them directed to such as your Facebook event, fan page, group or perhaps you want them sent directly to your website. One thing that is rather nice about using ads to promote your fan page or your event is that Facebook incorporates a button right inside your ad that when clicked, lets that person immediately either RSVP to the event or even better, to become one of your fans. They have made it pretty simple in that these people do not even have to stop by your page. When someone goes ahead and RSVP's to your event, all of their followers will see that activity being taken place out on the main wall and can trigger even more activity.
Advertising on Facebook is somewhat like Adwords in that you will be bidding on specific, targeted keywords and competing to get your advertisements shown. How successful you are at this will depend on the competitiveness of your selected keywords. You will need to decide if you would rather do a CPC (cost per click) where you will only pay for actual clicks or a CPM (cost per thousand model) where you will pay per one thousand ad views. It appears as if the cost per click model is a bit more effective according to some statistics. To begin your advertising campaign you must determine your bid per click and your daily budget allowance. Just starting out you will be testing the waters so set your bid per click right around the amount that Facebook will suggest, and a daily budget that you can afford, and about fifty dollars (or more) is what I came across when researching that amount. That seems on the high side to me so just use common sense and you can always adjust that amount to suit your advertising needs. Remember you're still testing the waters in the beginning.