Be sure that all persons involved are truly ready to proceed to sex. Discuss protection and/or birth control. Talk about what everyone wants to happen. Do not proceed without verbal and responsive consent. If any one seems scared (trying to brush the other person’s hands away, trying to hide, scared or nervous expressions, etc) stop and talk.
Go slow. Get comfortable. Cuddle. Kiss for several minutes. Foreplay for several minutes. Touch each other. Use lubricant. Be sure all individuals are aroused before penetration.
If anyone says “no” or “stop” at any time: stop. no exceptions.
http://www.cosmopolitan.com/sex-love/advice/first-time-sex
http://www.health24.com/Sex/Great-sex/Top-tips-for-first-timers-20120721