Spend some time carefully reading and annotating the first chapter Howard Zinn's groundbreaking, engaging history of the United States, which starts with the story of Columbus.
Read and annotate what Barack Obama wrote in a 2010 Proclamation about Columbus and the commemoration of his historic voyage.
Read and annotate an interview with Susan Shown Harjo, a 45-year-old Cheyenne-Creek, who has strong reasons for not wanting to celebrate Columbus and his invasion of indigenous people.
Spend some time with Matthew Inman on his site The Oatmeal (captured in images) and see what he has learned about Columbus. Annotate specific parts of the 11 images here, and take note of his suggestion for who to remember instead of Columbus. (See how to use the Commenting Toolbar for Large Images on NowComment.)