[edit] Steps

Dress to impress. Guys may say they like it when a girl shows some skin,(because they are visual) but really they like girls that are on the modest side,but it is okay to wear a dress that shows your shoulders, some leg and shows a little bit of your chest. If you're a little bit on the heavy side, then wear a nice blouse. But remember to be comfortable. Don't wear something with so much skin that you look desperate.
Wear some makeup. You should put on some lip gloss or lipstick that matches what you're wearing (unless its purple, black, or blue), something like brown or red or pink is good. A little mascara doesn't hurt and some eye liner. But don't over do it. You don't want your date thinking he is on a date with a clown.
Be polite. Don't say rude things and mean things. Don't criticize his opinion, that's a big turn off .
Have good table manners. When you are eating chew like you have a secret. Close your mouth when chewing and don't talk with your mouth full, you know this one, right?
Don't keep the conversation on you the whole time. If he asks you to, it's okay but don't tell him your life story or share personal or private information- if your relationship with him goes on longer than this one date, you can tell him later. If it doesn't, you probably don't want him knowing those things about you.
Make the conversation two-sided. Don't ask stupid questions or personal questions, but keep the conversation moving back and forth between you two. Ask him important things like what's your job, etc.

[edit] Tips

Always smile
Compliment him on how he looks. He'll compliment you back. But don't over do it.
Hug him after the date.
If he's polite, your date should be doing something along the same lines as this, excluding wearing makeup. (If he wants to, that's fine.) If he drifts off from these tips in a major way, he's probably rather rude, and may not be the best choice.