Harold Doan  
   Used, out-of-print, rare and antiquarian books. Searchable index of inventory.
   http://h-doan.tripod.com/

Haymes and Sons  
   Catalogue includes art, architecture, travel, exploration, military, natural history, sport, theology, fashion, theater.
   http://www.haymes.com/

High Ridge Books  
   Antiquarian and used books.
   http://www.highridgebooks.com/

Haven Books  
   A general used, rare and out-of-print bookstore; hardcover books with an emphasis on non-fiction, including antiques, military, railroad and aviation. Based in Winter Haven, Florida.
   http://havenbooks.org/

Heritage Bookshop  
   Antiquarian shop specializing in books and manuscripts.
   http://www.heritagebookshop.com/

Horizon Books  
   Travel, voyages, exploration, natural history and gardening; rare, used, antiquarian & out-of-print books.
   http://www.horizonbook.com/

Hillside Books  
   Books on insects and related topics.
   http://www.insects.demon.co.uk/

Henry Hollander, Bookseller  
   Antiquarian and scholarly bookstore specializing in Judaica.
   http://www.hollanderbooks.com/

Heritage Books  
   Rare and hard-to-find books in many categories; also ephemera.
   http://www.heritagebks.com/

Hidden Staircase  
   New collectible and out-of-print books, as well as gift items.
   http://www.hiddenstaircase.com/

HarbarCollectibles  
   Used and rare books, including militaria, naval, aviation, and railroadiana.
   http://www.HarbarCollectibles.com/

Hardback Hotel  
   Modern First editions, collectable Fiction. Out of Print Booksearch service
   http://www.hardbackhotel.co.uk/

Hawsbank-books.co.uk  
   Secondhand reference books and non-fiction texts for sale, listed by category with description of contents.
   http://www.cumbrianscoobs.co.uk/hawsbank_books/index.htm