It's hard for me to give you an advice. The books are just great, but they are translated into English from Polish and unfortunately the translation isn't that good. Due to that English readers might miss quite a few details and subtleties. They are definately worth the try, but if you look at Reddit, you will see a lot of people that liked the show and decided to read the books... And then stopped enjoying or outright hated what Netflix did. I mean, really, the second season has almost nothing to do with the books and that's why fans like me are furious.
If I were you, I would try reading the first book, "The Last Wish". It's a collection of short stories, connected with each other. The first season was based on it and it is regarded as the best book in the Witcher universe. It won't spoil you a thing, so give it a try and see, whether you like Sapkowski style or not. If yes, just keep on reading the second short story collection ("The Sword of Destiny") and the main saga. The second season of the show is supposed to be the adaptation of the first book in the saga, "The Blood of Elves". It's a really slow and short novel, which is something like an introduction to the main story. Everything will rock in the second book, which is to be adapted by the third season.
Anyway, thanks for reading my review and have a nice one!
RE: The Witcher: Season 2 is terrible... But I still enjoyed it!