First of all, all of u need to knw that not all women are the same. It might take some women two mins, some two hours and some NEVER to orgasmic. It might also depend on how the woman feels about the guy. It can also have to do with if the man is pleasing the woman. But if u are mature and u are having sex it is important to ask your partner what pleases her or him that way u know u are doing the right things. Find out what your partner likes...ask her what turns her own. she may want u to whisper in her ear or just stare into her eyes or spank her lol. To have great sex u need to communicate. And remember there will be women who will never reach an orgasm...just doesn't happen. Rest assure the problem might not be u...talk ot her about it!
sanai has pretty much summed everything up.