it would probably be better to read them all in the order in the list and not jump ahead to WA and L&L etc
and if you are going to jump ahead to WA, you should read Equal RItes first as that introduces witchcraft to the Discworld books and establishes the character of the main protagonist in WA and L&L
the other difficulty in reading them out of order is that although there are the Death books, the Witches books, the Wizards books, the Watch books, etc, a lot of the characters appear in many of the different "collections" but those characters refer to things that happened in a book inbetween 2 of the books in the collection, and although not vital to the plot, in most cases, you do miss some of the in-jokes