Sidney T. Black Publishing, Inc. - Fiction and non-fiction by political activist David Truskoff. Includes biographical information about author. - http://users.erols.com/suttonbear/
Sam Weller's Zion Bookstore - New, used and rare titles. Includes a newsletter and regional picks. - http://www.samwellers.com/
Stackpole Books - Publishing books on fly fishing, nature, outdoor sports, crafts and hobbies, history, civil war, and military reference since 1927. - http://www.stackpolebooks.com/
Siso Books - Publishers of books related to religious, epics, computer, tales, dictionaries, grammar, classics; both in English and Malalyalam languages. - http://www.sisobooks.net/
Sunstone Press - General interest books as well as non-fiction books featuring the American Southwest. - http://www.sunstonepress.com
Self Help Guides - Easy to use, and professionally written guides on many topics. - http://www.selfhelpguides.com/
Santi Books - Focus on health, spirituality, environmentalism, and well-being. - http://www.santibooks.com
Sociosights Press - Featuring "Katherine Stinson: The Flying Schoolgirl," a biography of an aviatrix. - http://www.sociosights.com/
Schiffer Books - Titles on antiques and collectibles, military collectibles and history. - http://www.schifferbooks.com/
Substance Books - Links book sales to authors. - http://www.substancebooks.com/
Seaview Press - Self-published books, mostly from Australia and around the world. Includes details of the self-publishing process. - http://www.seaviewpress.com.au/
Student Book World - New textbooks in categories - or search. - http://www.studentbookworld.com/
Sacred Spaces - Selection of books and products related to a group of authors. - http://www.sacredspaces.org/
Sapna - Showroom for books located in Bangalore - India. - http://www.sapnaonline.com/
Shakespeare and Company - Online bookstore selling books in all categories. - http://www.shakeandco.com
Sands Publishing - Fiction and nonfiction books in most genres, including general, suspense, romance, mystery, sci-fi, children's, spiritual, and memoirs. - http://sandspublishing.com
Swot Books - Textbooks and general list from the UK for students and academics. - http://www.swotbooks.com/
SeekBooks Australia - Large catalog by subject. - http://www.seekbooks.com.au/
Sleeping Bear Press - Golf, children's, turfgrass management, health and nature. - http://www.sleepingbearpress.com/
Savage Press - Selection of books on a variety of subjects. - http://www.savpress.com/