I did notice that the "reading order" on that HC website was only posted after Sir Terry passed away.
I wonder why that might be?
Seriously though, read the NPR article BenG posted last year.
There's No Wrong Place To Start Reading Pratchett. They discuss
why it can be best to read some of these out of order.
Reading out of order is
not necessary, but it can be done without
ruining later/earlier books. And for some people can
improve those later/earlier books by doing so.
For any new readers of Pratchett, there are obviously some strong opinions about this topic. Take a few minutes to read the NPR article above and then decide if you are comfortable starting someplace other than the first novel. If you aren't comfortable doing that, reading in published order is not
wrong. It just might not be the best place to start because the first couple books are some of the weakest in the series. If you are comfortable starting elsewhere, there are a
couple charts around with suggested start points. Take one of them and run with it. If you find you like one sub-series you will probably be back for the rest of them at some point.
Anyway, I think it is time for us to take a step back and find a good book to read. My next will be
Small Gods as I go through them in published order this time.