Consider the sources listed as starting points. Be sure to look at the cited references, and if the source is a book, look to see what the subject headings are.
Be careful not to overgereralize. Immigrant groups will include smaller subgroups. For example, if you choose German or Polish immigrants, you will probably want to distinguish between Catholics, Jews, and Protestants. Groups came over in different "waves." Not all Irish immigrants were part of the wave that came over during the famine in the 19th century (who were primarily Catholic)--there was also a wave of Scotch Irish who came over in the 1700's (who were primarily Protestant). The earlier German Jewish immigrants were far different than the Eastern European Jews who came over later. Religion played an important role for many immigrant groups, somethng you should keep in mind. Also remember that there were also ethnic differences within various religions (notably Italian and Irish).
Keep in mind that you will need to get some general background information about whatever group you choose. While locating journal articles about a group's educational experience may seem the most efficient option, remember that articles are generally written about fairly narrow topics, and you will also need the "big picture," something usually better provided by specialized encyclopedias and books.
American Education, the Metropolitan Experience, 1876-1980 by Lawrence A. Cremin
Chapter 3. Patterns of Diversity
The American School, 1642-2000 by Joel Spring
The Children of Immigrants in School, a chapter in The Immigrant: An Asset and a Liability by Frederick J. Haskin
A google book. Published in 1913, the author reveals many common attitudes of the era.
Democracy and Assimilation: The Blending of Immigrant Heritages in America / Julius Drachsler
A google book that was published in 1920. It primarily addresses European immigrants. Of particular interest may be chapter 7, Americanization, starting on page 191.
Gale Encyclopedia of Multicultural America
Useful because entries specifically address assimilation of individual ethnic groups.
One Best System: A History of American Urban Education / David B. Tyack
Note: "Cultural Conflicts: Religion and Ethnicity" (starting on page 104) and "Americanization: Match and Mismatch" (starting on page 229)
See index for various ethnic groups.
The Public School and the Immigrant Child, 1908.
A google book. This classic report, written by Jane Addams in 1908, reveals her concerns about some common attitudes at the time.
Schooling of the Immigrants by Frank Thompson
A google book that was originally published in 1920. It illustrates many of the attitudes of the time, particularly in regard to language.
The Social History of American Education edited by B.Edward McClellan and William J. Reese
Chapter 13: The School Achievement of Immigrant Children: 1900-1930
Turning Points in American Educational History by David B. Tyack
Chapter 7. Becoming an American: The Education of the Immigrant
Chapter 8. Growing Up Black: The Education of the Negro
Working Toward Whiteness: How America's Immigrants Became White: The Strange Journey from Ellis Island to the Suburbs / David R. Roediger
Relevant sections on Chinese, German, Irish, Italians, Japanese, Jewish, Polish, and Black Americans.