improving sex life

I am in love with a girl & she loves me too but it's been 1 year of relationship that we haven't had real sex. She just fore played with me & used to stop there. I think she was scared of having sex. I had tried several times to ask her as to why she doesn't do it but she was unable to give a concrete answer. But to my luck stars she did have sex with me and there was a problem of premature ejaculation. I have had sex earlier a few times but this sort of problem never aroused …….I think this was the first time with her...so!!!..Please let me know any good ways or material which can make me more known to having good sex and being comfortable with it.