Men want a woman who is clean and well dressed.
Men want honesty. Don't ever pretend you are someone you are not on a date. What if this turns into something more than a date. You don't want to have to explain your way out of a bunch of lies. This is not a good way to start a lasting relationship.
Men like to be treated like men, not like little boys. Don't try to be his mother. You will knock the legs right out from under him if you try to teach him manners or etiquette or brush the lint off his shirt.
Men like to think they are important. Let him talk about himself and pay attention to what he says. If you get to a second date with him, it will really boost his ego if you talk about something he has already shown an interest in.
They also want you to be interested in what they have to say. Don't look around the restaurant while he is talking to you. Don't let your eyes glaze over. Take mental notes. You will need this information if you go on a second date with him.
If you are setting the date up, try to set the stage to his likes. When you are using an online dating service, you will have a lot of information about your date before you even approach him. Base the experience around his likes, not yours.
Men like compliments. Tell him he looks nice and smells good. Men are very insecure on a first date. Break the ice by letting him know that he did good. Don't get carried away with your compliments though. It isn't natural to do this and it can be down right embarrassing.
Ask him about himself. Give him something to talk about. Don't get too personal. You don't want him to think you are husband shopping. This will scare him away even if he is wife shopping. Men like to think they made the decision to continue the relationship.
Don't go on and on about yourself. Give him a chance to talk too.
Never, ever talk about past dates with other men. Don't mention your ex-boyfriend or ex-husband. He doesn't want to think you are comparing him to some other man.
Finally, just because he bought you dinner, this doesn't mean you have to sleep with him. Men will respect you if you say no. They really want you to say yes but if you do, they will think you are easy and won't want to see you again. Or if they do want to see you again, it will only be for one thing.