The chronology of Witcher books:
"The Last Wish" was a series of standalone short stories. "Sword of Destiny" is a series of short stories, but they are tied together more closely, and they lead directly in to the novels, so "Blood of Elves" and future books might be confusing without it.
"Sword of Destiny" doesn't have an official translation in English because the publisher doesn't think short stories sell well, and "Baptism of Fire" and on aren't translated quite yet. The fan translation of "Sword of Destiny" is high quality. The translation of "Baptism of Fire" is low quality, but better than nothing. The translation of "The Swallow's Tower" is medium quality.
The things I liked about The Last Wish (and the things I disliked) are all mostly true of the remaining books. I think I prefer the short stories to the long narrative, but both are good.
I will note, though, that the description of war in Lady of the Lake is one of my favorite chapters in any book. Rather than focusing on heroes and ignoring the fallen, Sapkowski tells of a battle from the perspective of a medic's tent. I wrote a comparison between war in The Witcher and a glorified fantasy description of war when I wrote about Furies of Calderon.