1. How do you keep track of your TBR pile?
We have a three-shelf bookcase in our bedroom with the majority of the TBR selection (both mine and pennski's), plus an overflow shelf in the built-in wardrobe. They are usually sorted into one of two orders: by date bought or by author - more often the former ('guilt order' as we tend to refer to it!) Note that this excludes the large selection of unread Doctor Who books and science fiction magazines which are in separate bookcases downstairs. Also any books which pennski has read and I haven't go on the bottom shelf of my bedside table (and vice versa).
For ebooks, I have an 'unread' category on the Kindle.
2. Is your TBR mostly print or ebook
The vast majority are print - though I'm prone to getting the ebook version as well if it's a particularly long (over 500 page) book for ease of reading! But I've got around 50 books that are only in the ebook version to read.
3. How do you determine which book from your TBR to read next?
It's a mixture. Right now I've separated out the books which have been bought as gifts over the last few years and I'm trying to catch up on those. Sometimes I try and catch up on outstanding hardbacks. Sometimes I try and catch up on books that are older, sometimes clear down where I've got lots of books by the same author (I think C. J. Cherryh is the current winner in the category with four.) And once in a while, when I get in a rut, I'll chose randomly using dice!
4. A book that's been on your TBR the longest.
Excluding the Doctor Whos and magazine (for that way lies madness!), the oldest currently on the 'to read' shelf is Farah Mendlesohn and Edward James' A Short History of Fantasy, which is dated 6th June 2010.
5. A book you recently added to your TBR
ebooks aside, the last books added where various Christmas presents off my Amazon wishlist, including The Best of Lady Churchill's Rosebud Wristlet (ed. Kelly Link and Gavin Grant), The Gate to the Women's Country (Sheri Tepper), The Golem and the Djinni (Helene Wecker), a book about the history of post-war UK musical theatre (a uncommonly apt gift from my parents-in-law!)
6. A book that will soon be added to your TBR
I'm trying not to buy any books for a little while to get rid of the double-stacking of the overflow shelf, but once I feel free to expand again priority is the new Karen Lord (The Galaxy Game), the new Kelly Link collection and the final volume of Adrian Tchaikovsky Shadows of the Apt series.
7. Number of shelves used to house your TBR
Four and half for the 'main' TBR (although that also includes books that only pennski will read), plus another two and half of Doctor Who books, plus a large number of shelves with old SF magazines (I've got a complete run of both Fantasy & Science Fiction and Asimovs, many of which remain unread, plus I'm about 5 years behind on Interzone which is my next priority on the magazines)
8. On a scale of 1 to 10, how painful is it for you to discard will-never-be-read TBR books?
Oh, I'd say about 5. I've got much better at giving books a go and if they are not engaging me for some reason after 50 pages or so, giving up. Sometimes discarded books will actually go on the 'read' shelves if I think there's a possibility that I might one day be in the mood for them (or if they are part of a set), otherwise they'll go to a charity shop.
9. A book on your TBR that basically everyone has read but you.
Of recent books, Ancillary Justice by Ann Leckie. This won pretty much every sf award last year, but I've just not got around to it yet.
10. Name your sources of powers - where do you get your books from?
A mixture. Some are presents. If I'm going to buy the physical book I'll try and get it from my local Waterstones first, but if not I'll go to Amazon (I don't have any independent book shops anywhere near me, alas). Then there's conventions; I can't count the number of times I've started reading books by an author because they impressed me on a panel at a convention, though of course this is not necessarily a direct correlation - there are people I love dearly but cannot stand their writing and vice versa.
11. A book on your TBR that you're dying to read
Too many to list. Ancillary Justice as mentioned above, Kameron Hurley's Infidel and Mirror Empire, The Golem and the Djinni, an unread Ken MacLeod that's been sitting there for a couple of years, etc., etc., etc... This is one of the reasons, incidentally, why we rearrange the order of the shelves once in a while. It reminds us of what we've got!
12. A book you'd recommend others to add to their TBR shelves
Karen Joy Fowler's We Are All Completely Beside Ourselves is great. Also, wearing my Carl Brandon Award juror hat from a couple of years ago, both the winners - Karen Lord's Redemption and Indigo and Nnedi Okorafor's Who Fears Death - are both really good in very different ways (though I would say that, wouldn't I?!)
13. Is your TBR a force for good in your life?
Yes and no. For the first five years or so after we got married we didn't separate out our TBRs, we just ended up missing them and rereading other books. Since we separated them out, there's a tendency to go too far in the other direction and feel pressured to only read 'unread' books and not reread. Which is a shame because there are loads of things I'd like to reread (a complete Patricia McKillip reread is in my future...)