Here are a few links I’ve found useful in my historical research. These are all collections/archives of contemporary materials. Contemporary to historical periods, I mean.
Old Magazine Articles, edited by Matt Jacobsen. “OldMagazineArticles.com is a Los Angeles-based website; privately owned and operated, it is the effort of one old magazine enthusiast in particular who believes deeply that today’s readers of history can learn a good deal from the old periodicals. It is a primary source website and is designed to serve as a reference for students, educators, authors, researchers, dabblers, dilettantes, hacks and the merely curious.”
The Home Economics Archive at Cornell University contains full-text articles and books from 1800-1999.
The Life Magazine photo archive, covering from the 1860s through the 1970s.
The Early 1900s in Color. This was a blog post at Citynoise.org that features a collection of color photographs from around the world.