Scholar OneSearch is the best place to look for books and e-books that Northeastern has access to. Search results will include a variety of materials including books (both print and electronic), articles, videos, data sets, and more. There are many useful filters in Scholar OneSearch to help narrow down your results, including a material type filter on the left hand side of the results page.
Try using Northeastern's Interlibrary Loan system to request books, book chapters, or articles not available at NU. Articles can be delivered electronically.