One of the easiest ways to build a contact list, and also the most effective, is to get a referral from someone you already know. In fact, Facebook was created on this premise when it originally was created with a closed network that you had to be invited into by someone else to access. This is no longer the case, and you can simply choose to sign yourself up without a referral from anyone.
However, then you find yourself in Facebook and you're all alone! Instead of sending out emails to anonymous people, you should always start to try to build your network with people you already know who are on Facebook. This way you never find yourself in the position of having to make an email cold call. Someone will have already introduced you as a friend. This will give you a degree of credibility when you go to approach people you don't know on Facebook, who you would like to get to know. If you have no friends, you can bet others will not trust you as easily as if you have a few friends on your side already willing to vouch for you.
When you sign up, you will be asked for a variety of personal information. You should be truthful with where you went to school, where you live, and where you work (if you don't mind an employer finding out you are on Facebook).
Some people have even tried using screen names, but found that when building a business, it makes more sense to use your own name. After all, hopefully you are not online to post pictures of the latest frat party, but rather to make money. So, if you keep to some decent business standards, you shouldn't have to worry too much about using your own name and it can help to start to brand you as an expert in some field.
The reason for using your own personal information is because you are going to use it to find your friends! If you go in and can find no one there who knows you, you will have to start trying to make friends, without having any friends to speak of. That's like being the new kid in school who no one knows, no one trusts, and everyone thinks is a bit weird. Friends are important because they can help you establish your identity and verify who you are. And, identity is everything in social networking.
So, after answering the profile information, you can start to look for people who might have attended school with you at some time in the past, your prior co-workers, and even people in your specific geographical area. Another great way to find people you already know on Facebook is to think about the types of organizations you have joined in the past. Is there a church you attended?
Plug in the church name in the friend finder and you will be surprised how many people pop up. Any organization is fair game, whether it is a library book club or a business organization. It doesn't hurt to look and it can be a great way to establish a presence from the physical encounters and time you've already spent doing your regular activities in your area.
Source: Profitable Freelancing with Facebook