English Language Arts CC standards require students to read and analyze non-fiction. An excellent way to teach these standards is through Independent Reading, and you can coordinate with your Social Studies teacher in the same grade to see that students read material that builds on both their ELA and SS CC reading requirements. It is an excellent way for students to begin building background knowledge of U.S. historical events taught in 8th grade, as well.
The Reading Responses address ELA CC Standards 7.RL.8, and the project assignment addresses ELA CC Standard 7.RL.6, and most of the ELA CC Standards for RI, or reading informational (non-fiction) texts.
I've attached the second quarter Assignment Sheet and a list of 75 non-fiction books pulled from Fairfax, Virginia schools' recommended reading list in 2013. The list is a few years old, but contains many excellent selections at all reading levels. There's sure to be something that will interest your students.
My students always raved about Hillenbrand's book!