How do I marry an illegal alien and is it easy?

I fell in love with a man who came into the United States illegally. We want to get married and also try and get him some sort of citizenship so he can legally be here. He went to school here, graduated high school, and even attended some college but was unable to finish due to his illegal status. How do we go about this process? Should we consult with a lawyer first? And if so, are there any recommendations as to whom?