jeetu,
It takes some time before a woman becomes receptive to having sex after childbirth. It is a traumatic experience for a woman to give birth to a child. The delicate tissues in the vagina are strained, bruised and torn and takes time to heal completely. There are also hormone changes and emotional stress which puts women off sex for a long time.
Generally, doctors advise that sex should wait for atleast 6 weeks, till after the mother has had a post-natal check up. This is the time for you to be considerate to your wife and resume sex only when she is ready for it. Do not force her. You can relieve your sexual stress either by masturbation or ask her to masturbate you. Penetration can wait.
You can have foreplay with your wife and even if she orgasms there will be no danger to her. Asking her to give you oral sex, is also a good idea. But not the other way around. You should NOT perform cunnilingus (oral sex) on her, as this could lead to an infection, which may be transmitted into the vagina and the womb.
After childbirth, it is okay to handle the breasts, but again your wife should be happy with it. It may be better to feed the baby and empty the breasts of milk, before you caress the breasts or be prepared for jets of milk flowing.
A woman sometimes experiences Post Natal Depression, which puts her off sex. Be patient and wait for more time.