I always read Jon's columns, they are informative and interesting no doubt. I just don't buy these books. I'm already busy enough with reading the regular prose novels as it is.
I got into autobiographies when I was in middle school, and I continue to read them, in no particular pattern, to this day. Some that I remember especially are Agatha Christie's autobiography, Ngaio Marsh's (as I mentioned already), Frank Capra's autobiography, Lilli Palmer's CHANGE LOBSTERS AND DANCE (I'm sure I bought it for the title). I'm currently reading a short story collection: THE BODIES IN THE LIBRARY, 2, and I'm really enjoying the pocket biographies following each story. The first autobiographies I remember reading were in a special edition made for school children - one was about Clara Barton and one about J. Edgar Hoover and the FBI. I don't know if Mary Stewart or Josephine Tey ever wrote autobiographies, but if they did I would snap them up in a minute!
I also buy reference books on writing and about mysteries and the people who write them. I love to find unusual editions - for instance, my husband and I came across a lot of graphic novels based on Agatha Christie's books and he gave them to me for Christmas that year. :-)