credit card rewards point?


I just applied for a credit card that gives you rewards point, don't really need a credit card but I got it cuz I'm 25 and want to build credit as I'm thinking of buying a house soon. My question is will they give you points for just buying gas, beer, and pizza? Cuz I was just thinking of telling my friends that I'll buy beer with my credit card take their money and pay it off at the end of the month to build credit faster. Will my credit score go up with just buying beer and gas and will I still get my rewards point? It is a basic Citi Bank Rewards Card.
I was thinking maxing out the credit card and then paying it off at the end of each month with all the money I save.

My job involves creating credit cards for companies like United Airlines, so I know about this.

Your credit score is a quick way for creditors to judge how you have done with loans (which is what credit cards are). So if you have a credit card for a long time and have always paid what you promised to pay, on time, then it will help your credit score. But if you buy beer with your card, collect money from your friends, but don't pay your card on time because you, like most 25 year olds, spent all your money, and the money you collected from your friends on something else (let's say a new PS3), then your credit score will go down because you were late. As for the rewards points, it really depends on which card you have. Call your credt card company and ask them what they offer.