HERE’S some (tip of the iceberg, really) suggested reading from the Warhammer 40,000 library. Look for these books on the science fiction shelves of major bookstores or online retailers – or go directly to the source, Blacklibrary.com.
Many out-of-print titles are now being made available again either as e-books or print-on-demand titles, so you can play catch-up ... for a price. Ordering these books online is pretty safe, I’ve only had one parcel from the publisher out of over a dozen go missing (and Black Library, bless ’em, replaced it).