Amy Hubbard, casting director, gives a great insight into casting The Hobbit and The Lord of the Rings and talks about Peter Jackson, Ian McKellen and Elijah Wood in this Film Club video.
In another interview, this time with blogtalkradio, Amy talks about The Hobbit (at 24 minutes) and how Peter Jackson always leans towards actresses who are the same ‘type’ as his partner Fran Walsh, how amazed she was seeing Richard Armitage in Thorin’s costume (at 32 mins) and how Bard was the hardest character to cast until Luke Evans came along (at 33 minutes). The interview starts at 5 minutes.