Please go to your profile page and open Referrals page. All the details are given in that page. If you have any doubt after reading that page you can post your problem here. Any member or Editors will guide you. Please remember for each referral you will get points and for more details please read New Members FAQ.
Amar Nath Das
You can invite your friend by "my referral" just copy the link and mail through your mail.
Best of luck.