you'll have to wait for aroudn a year before you can get larger credit cards with signup bonuses Like cardinalkid said just try to get your foot in with starting cards such as discover student, maybe a secured card. Also, if you have a checking/savings account with a certain bank they may be more willing to help you open a credit card. Once you have that pay in full every month and you credit score should be around 740 in one year. At that point you have around the minimum score+credit history to start being approved for major cards.

I think the Chase Freedom would be the ideal card to start IF you can get it. I've heard people being approved without any credit history. However, chances are you will not and it is a good card to get around 6 months in.