Okay, this one's a bit of a mess and I've seen it trip people up constantly. The biggest thing with 'Monogatari' is you absolutely cannot watch or read it in simple anime release order if you want the pure, unspoiled experience. The anime adaptation shuffled things for production reasons, and following that order will ruin some of the best narrative twists. Like, if you watch 'Kizumonogatari' after 'Bakemonogatari' like the anime suggests, you've already been told a bunch of stuff about Shinobu and Kiss-shot that the novels intentionally keep as a slow-burn mystery. The novels drip-feed her backstory over several arcs, and the 'Kizu' movies just dump it all out early.
My method, which I think is the cleanest, is to follow the novel publication order, which Nisioisin intended. Start with 'Bakemonogatari' Parts One through Three. That's your foundation. Then jump to 'Kizumonogatari'—it's a prequel, but you need the context from 'Bake' to appreciate it fully. After that, it's 'Nekomonogatari: Black', then 'Nisemonogatari', and 'Nekomonogatari: White'. This order preserves the reveals about Hanekawa's family situation and the true nature of the Bee apparition. The anime jumbled 'Neko Black' and 'White' weirdly.
From there, you head into 'Second Season' territory with 'Kabukimonogatari', 'Hanamonogatari', 'Otorimonogatari', and 'Onimonogatari'. Important note: the novel 'Hanamonogatari' actually takes place chronologically way later, but it was published here, and reading it in publication order gives you crucial foreshadowing about a certain character's fate that hits much harder. The anime moving it to the very end was a huge disservice, in my opinion. Then it's 'Koimonogatari', finishing the Second Season arc. After that, 'Tsukimonogatari', 'Koyomimonogatari' (don't skip the short stories in 'Koyomi'—the last two are vital), 'Owarimonogatari' Parts One and Two, and finally 'Zoku Owarimonogatari'. It seems complex, but it flows perfectly when you read it this way, with each reveal landing as intended.