Read other materials besides the required textbooks. If you're writing an informative essay on negative stereotypes of Arab-Americans in film, visit the library and read scholarly journal articles on this subject. Then refer to your textbook on how to organize the essay.
Get acquainted with the authors that relate to the course you're taking. If you're taking a course on modernist literature of the early 20th century, find books on authors such as Gertrude Stein, T.S. Eliot, Henry James, F. Scott Fitzgerald and William Faulkner. Also read credible websites on this subject.
Visit your campus writing lab. Tell the tutors your specific difficulties and take notes during the session. The tutors may also be able to reccommend certain study guides that will improve your success in the courses.
Talk with your professors. For example, if you're assigned to write a research paper on the transfer of African-American oral tradition to literature in the early 20th century, discuss the direction of your paper with him. Your professor can give you pointers on how to organize it.
Get help from classmates. Suppose you're not able to get a certain required textbook because the bookstore ran out. A classmate can let you borrow the book if he is finished using it.