How do u make a female have an orgasm?

Well, there's the obvious, hit the G spot. But also, girls are very different with sex from men. The only time that I have been able to orgasm has been when I was emotionally lost in the moment. Hype up the romance and the personal care, she'll get lost in you and not be able to think straight, and once she stops thinking about how it feels....she'll start actually feeling it.

making a woman orgasm through penetration is primarily about two things:
1.) Her Psychology
2.) Her Physiology

If this has started to sound like a science lesson don't worry, i'll simplify everything into language we men really understand:

Psychology - this put simply means that you put a woman in the mood for sex. Sometimes this means acting like a caveman, she gives you that look, you've just had that argument, you're out and about in a public place and she kisses you a little more passionately than usual. The simple fact is that understanding this aspect of making a woman orgasm is a matter of guessing correctly which mood she is in or actively putting her in the right mood, this may variously be a strong manly grab around the waist or handing her a glass of wine after a hard day at work, setting up candles and running her a bath etc. etc.

Now most of the confusion on this subject comes from the very unhelpful fact that overwhelmingly the advice given on the internet focuses on these 'psychological' elements because for women, they are the more important.

As a man what you need to know is this and i'll get the boo/hisses from any girl reading BUT, as a man you need to focus on her physiology in order to make her orgasm through penetration. It's simply a fact that 70% of what will make her orgasm in penetration is simply remembering this:
Always Be thinking 'Clitoris'... ABC...

What this means is that you need to forget what you watch on porn, forget those Tom Cruise movies where the man always raises himself up on the strength of his arms in a romantic, intimate eye lock and over exaggerated pelvic movement... No... When you're performing in any sexual position you need to be stimulating the clitoris, this means always guys! There are two ways to make a woman orgasm - through her clitoris and through her G-Spot - the Clitoris is by far and away the easiest. This means, when you are:

1.) In Missionary - always have your pelvis griding as close as physically possible to her pubic bone, directly on top of it, causing as much friction against the area of the clitoris as possible. If you want to go for the G-Spot, put a pillow or sometimes even two under her buttocks, this both raises her public bone up so that you can grind more closely against it and also by lowering your waist towards the bed and thrusting 'up' against her front wall, you'll be maximising the pressure on her G-Spot area;

2.) Her on Top - ABC - always be thinking clitoris. If she's sitting on top of you, use your hand on her hips to pull her down on your shaft so that the bottom of your shaft will be connecting directly with the clitoris. Equally, if she leans over to kiss you, use your hand on her hips to grind her pelvis forward and backwards so that it is grinding directly on the clitoral area.
Those are two basic tips but the essence of how to make a woman orgasm through penetration resides in the ABC rule.

Now to jump back a stage, once you've firmly got it into your head to ABC, remember this as well, foreplay is the part of sex where you have most control over her body. It's where you can tease her, stimulate her, frustrate her, annoy her to your hearts content.

A good penetrative orgasm will start to build with your mastery of foreplay. Take your time, undress her, kiss her whole body (but for example don't go near her vagina), take your time to explore her and stimulate all of her erogenous zones (which you should know, if you don't start reading up on them!) you will notice that eventually she'll start pulling you up because she wants you inside her. When she is at this stage and you enter her, then ABC kicks in. It's close, it's animalistic, it's grinding and sweaty, it's not the Tom Cruise tricep marathon, it's a matter of pressing your lower half as strongly against her lower half as you can and taking long measured strokes...

Do this, spend some time with the foreplay, then ABC all the way through intercourse and you should be making that woman orgasm each and every time through penetration...

If you need more advice some good places to look are:
amazon.com - lots of books on the subject; or my particular favourite guide
therealplayers.com - a short lunchtime read packed full of information that you can put into practice straight away the same night (but it's a typical hard sell site which is slightly off putting!)...

Anyway, learn about her body first and let the rest take care of itself... Hope that helps!