Complex sentence: It was a newsletter of a dozen or so pages, produced on a typewriter, copied by a mimeograph, and hand stapled, that included book reviews, news, poetry, short stories, letters from readers, and news of DOB meetings.
Split into simpler sentences: It was a newsletter of a dozen or so pages, produced on a typewriter, copied by a mimeograph, and hand stapled. It included book reviews, news, poetry, short stories, letters from readers, and updates from DOB meetings.