Needs help on giving girls orgasums?

Make sure you spend a good amount of time in the foreplay region women love the build up and anticipation. So build anticipation wear ever your can. Bring some chocolate syrup and take turns licking it off each others bodies.

All the assertions made so far about foreplay are spot on. Female arousal response is heavily based in emotion whereas ours is rooted in the physical. The level of a woman's arousal and the intensity are heavily correlated with how attracted she is to you on the non-physical channels. That said there are plenty of purely physical techniques you can use to give a woman intense orgasms. Most involve multi-tasking and manipulation of the clitoris.

#1
During intercourse both you and your partner lie on your side, with you behind and her facing away from you and enter her from behind. Once you're in rhythm and things are moving along put your uppermost (left if you're on your right side and vice versa) hand between her legs and begin massaging her clitoris. Also you can bring your other arm underneath her and around her neck in a sort of soft headlock way. This provides you with a little more leverage and as an added bonus some women enjoy the feeling of your arm around her neck.

#2
With her on her back, legs spread, and you lying on your stomach with your head between her legs begin going down on her. Insert a finger or two inside her, palm up and make a beckoning motion. You'll notice a rougher, spongy mound on her anterior vaginal wall known as the G-Spot. While you manipulate this mound with your fingers, use your tongue to manipulate her clitoris. This method can actually lead to her "squirting" if she allows herself too (though many women have reported that the pressure felt before the orgasm feels almost like intense need to urinate and suppress it out of fear instead of letting it happen, which is why many women can't ejaculate). The most important thing to remember about this method is to start slow and slowly increase in speed. Listen to her. Many women will tell you to slow down, or go faster or not to stop. When she begins really moaning or tells you not to stop KEEP DOING WHAT YOU'RE DOING! Don't speed up, don't slow down, don't change anything.

These are two pretty solid techniques and have worked on most of the women I've slept with. But honestly, every woman is different. Some women like to dominate, some like to be dominated. Some like it slow and sweet, others like it fast and rough. Some like to be romanced and some like to be cave-manned. The key to pleasing all of them is versatility and being able to recognize what is turning her on or off and adjusting to what works for her.