To get the most out of Facebook, you will want to connect with your friends and family. Facebook makes it easy to find people you know and add them as your Friends.You can even find old classmates, colleagues and people with similar interests. Facebook is set up to encourage you to find Friends by allowing Facebook to access and import your contacts from your email and various other social accounts.
Facebook uses this information to connect you with Friends and to make suggestions to you based on your contact list.For some reason Facebook no longer allows you to import your Gmail account. (as of March
2012) You will have to add those names the old fashioned way.
Copy and paste ! If you don’t want to give Facebook access to your accounts and contact lists, then you can search for Friends individually or through networks, like city, employer, or school. Or don’t add friends at all this way. You may choose to join other Facebook Groups (search for whatever you are interested in) to find / add friends. You can make great new friends this way as well.
"Facebook Tips: How to find friends"
Reference : facebook101tipstricks.com