Google made a very nice logo to celebrate the birthday of Sir Arthur Conan Doyle with thousands of links to you visit. I have some suggestions of links about him too, in this and this post. More cool stuff in public domain or free to download:

- Episodes available at Radio Nostalgia Network: The Final Adventure, 2 Episodes, A Scandal In Bohemia Intro, A Scandal In Bohemia Part 1, A Scandal In Bohemia Part 2, The Speckled Band Intro, The Speckled Band Part 1, The Speckled Band Part 2 and Sherlock Holmes.

- Films available at Internet Archive: Sherlock Holmes and the Secret Weapon and Dressed To Kill.

- Sir Arthur Conan Doyle's e-books available to download or read on-line at the Project Gutenberg.

- "The Ring of Thoth" - audiobook available at Internet Archive.