Cronin family

Hi.  I have great grandparents from limerick. Denis Cronin and Johanna Guerin. They had the following children:  Dennis 1829, John 1838, Alice 1839, Mary 1842 and Bridget 1846. They arrive in New York before 1860. I was wondering if there was any research I could do to learn about this family. Any suggestions would be most appreciated. Thank you, Mary New York