^^Indeed. I didn't really pay much attention to Enterprise novels prior to the Romulan War series, but both it and the current Rise of the Federation have their own continuity while including things established in the 24th century novels like notable Federation politicians of the 22nd century and details about Andorian culture, naming practices and biology.
23rd century novels have a shared continuity in the Vanguard series (which gets mentioned in the 24th century) and its spin-off The Seekers. TOS novels are mostly stand-alone adventures with no real continuity between them, although sometimes a previous novel might be mentioned, or an upcoming one foreshadowed. Some TOS novels have also referenced ships, characters, planets, or alien races from the Vanguard series as well.
23rd century novels have a shared continuity in the Vanguard series (which gets mentioned in the 24th century) and its spin-off The Seekers. TOS novels are mostly stand-alone adventures with no real continuity between them, although sometimes a previous novel might be mentioned, or an upcoming one foreshadowed. Some TOS novels have also referenced ships, characters, planets, or alien races from the Vanguard series as well.