It is extremely important that you understand the privacy settings on Facebook. Should you choose to share e.g. photos publicly on Facebook, this means that everybody (not only your friends) is able to see this information. Ensure that your posts are just shared privately (i.e. with your friends). It is also advisable not to share personal information like your contact numbers and physical address on Facebook. Third party persons and web sites are able to access public Facebook information so ensure that you check your privacy settings before proceeding.
Review the tutorial below on understanding Facebook's privacy settings.