1. How did you come to read your first Discworld book?
Almost certainly by sheer chance. I was shopping in Waterstones and looking for a fantasy book, and I noticed among the shelves a book with little blue people on it. I think I compared them to Dobby the House Elf from the Harry Potter series, and being of fairly open wallet back then, decided why not? I think I actually took a while to get round to reading it, as I was interested in the Bartimaeus trilogy at the time. The name "Terry Pratchett" didn't mean a thing back then, and it certainly didn't make me break out in fits of knowing grins.
Ho hum.
2. What was your first Discworld book?
If you haven't guessed yet, it was The Wee Free Men. Considering the subsequent impact Terry Pratchett had on my reading, it was a fairly innocuous start: I cheered on the world's dissing of fantasy conventions, and was a little put off by the strangeness near the end. I still remember Miss Tick leading Tiffany on with that "When you wish upon a star..." reality check, and I can still nod in sympathy when Tiffany complains about a story in which nut-gathering occurs in the wrong season.
Sadly, I haven't touched the book much since then, and to this day I have only the haziest idea of what happened at the climax. It's probably symbolic of something.
3. Will you read more?
Wrong tense! I've already eaten my way through every single Discworld book up to Raising Steam, and I've devoured all his Non-Discworld books up to Dodger (give or take whenever World of Poo came out, as I haven't read it). Otherwise, I've occasionally nibbled at his supplementary Discworld works, like the Folklore of Discworld and the Science of Discworld series, and I've stared through the gourmet windows at his menu of most recent books without actually ordering any.
I'm no literary connoisseur, but finding Terry Pratchett's books has been like finding a five-star cake shop and then being told that the cakes can't make you fat. If he'd managed to double his Discworld output to 80 rather than 40, I'd probably have still had it all finished by now: I'm barely exaggerating when I say there was a year of non-stop Pratchett reading in my life. I still pop in for a quick bite of my favourite dishes every now and again.
4. Which one do you intend to read next?
Extended cake-eating metaphor aside, at the moment I'm debating whether to continue the Science of Discworld series and whether to start The Long Earth. I'd read the first Science of Discworld, and though the Discworld bits were worth the price of admission, I found the rest of it surprisingly tough to get through. I think it was mostly the non-Pratchett bits, as I found them a combination of uninformative (it didn't tell me anything I hadn't heard umpteen times already, though the recurring civilizations idea was a nice touch) and dull compared with the sheer fun of watching the faculty muddle through each stage of the Earth's development. The Long Earth series I'm considering merely for completeness' sake, as I'm of the raisindot school of thought that something went wrong with his writing style in the last few books.
5. If you didn't start with Colour of Magic, how easily did you find it to get into Discworld? Did you feel that some background knowledge was necessary?
I found it all too easy, though I'll admit scenes from The Wee Free Men have a lot more meaning after you've immersed yourself in Discworld for a bit. You can't even begin to appreciate Granny's presence until you've read exactly what she's done to earn her reputation.
Interestingly enough, I did end up reading The Colour of Magic as (I think) my third book, and roughly at the same time I read Thud!. They're two books from opposite ends of the Pratchett spectrum, but both were - in their own ways - successful in getting me well and truly hooked. If anything, the sheer range represented in them - one a dark, tense, and brooding police thriller with social satire and political overtones, the other a relatively goofy and anarchic mickey-take of stock fantasy tropes and mythologies - was the big draw. Any author who could pull off both and still make entertaining stories was an author to follow up on.
The only other thing to note is that I read the series almost entirely out of order, which gave the result a far more eclectic feel than it probably would have done otherwise. Of course, since Pratchett specialized in eclecticism to begin with, that merely enhanced the effect, but it did mean that I barely registered, say, Sam Vimes' character development or how Discworld technology changed over time. I think it says a lot for the series that this did nothing to effect my enjoyment whatsoever.