Encyclopedias have general information. They briefly describe the main ideas for different topics.
The first three books are in the library; the others are online (off campus you will be prompted to log in with your MyNOVA username and password):
The Newest Americans
Ref JV6455 .P57 2003
American Immigrant Cultures: Builders of a Nation
Ref E184 .A1 A63448 1997
Encyclopedia of North American Immigration
Ref JV6465 .P68 2005
This book has statistics near the end.
For individual research help, schedule an appointment to meet with a librarian.