I'm 29, British, and a book hoarder. It's something of a running joke in my family that I'm always reading, always want books for birthday and Christmas, and constantly run out of shelf space. Last count I had 1200+ books, many of which I haven't read. I mostly read children's and young adult. I collect school stories. I perv on cook books. For the full extent of the problem of my hoarding, see either my books owned list (which doesn't include all my nonfiction) or, worse, those I own that I haven't read.
For my favourite authors and books, please see my intro post.
Book Jay? Jays are like magpies, and I definitely have a tendency to go "ooh, shiny, I must have it" over books which are then placed on my To Be Read pile. I also thought of the jays on Kirrin Island in The Famous Five, who are constantly fetching stick - they never seem to stop doing this, they constantly collect.