there are two ways.. work from facebook by using their system to make money.. or apply on their site though its not that easy cause they are usaually loooking for local employees unless you have an xceptional resume
I think its best trick to build more n more quality friends (Group)..big group big marketing ..big money..
Create a Fan page about whatever you're interested in, like fishing, funny page, traveling, etc. Write good content on your fan page and engage as many as users possible. Once your page starts getting good response and good amount of likes, you can move to next step: Create a Website Related to your Fanpage. Now create a website related to your fanpage topic if you can afford everything. You can create free websites as well. Add contents to website and post on your facebook page to get visitors to your site. Add ads to make money and make sure your website looks decent and not copied.
You can create Facebook page and use it for promoting your things. Increase your followers, likes, comments etc. You can make money through Facebook ads.
create a page about your site and promote it. Facebook gives good traffic. If your page is more popular you earn more money.
You can earn from lots of ways by Facebook Here is some sample to earn money: 1. Natural Facebook Marketing 2. Facebook Paid Advertising 3. Product Promotion 4. Affiliate Program etc Actually Facebook is not a machine to earn money. But you can create a machine for earning. Improve your Skill about Social Marketing. Then Create an Earn Machine.
You can apply to their career page. If they have any opening matching your skills they can contact you. Best of luck