Many lessons can be developed around books that are in the public domain. The benefit here is that you not need permission to use their resources, and they are available for free online.
Consider the following:
My Father’s Dragon by Ruth Stiles Gannett
https://www.gutenberg.org/files/30017/30017-h/-h.htm

Journey to the Centre of the Earth by Jules Verne
(This is an effective selection for both social studies and science.)
Note the spelling of the title in the original text.
http://www.gutenberg.org/files/18857/18857-h/18857-h.htm

Teen-age Super Science Stories by Richard M. Elam
http://www.gutenberg.org/files/55801/55801-h/55801-h.htm
Don’t let the cover fool you. These stories are still interesting for young people.

These selections, while not in the public domain, are useful for further reading.

