Star Trek: Deep Space Nine takes place concurrently with the latter years of Star Trek: The Next Generation and the early years of Star Trek: Voyager. While the latter two shows were boldly going in their starships though Deep Space Nine was set on a space station, commanded by Captain Benjamin Sisko, near the planet Bajor and a wormhole to another quadrant!

You can find Star Trek: Deep Space Nine books set during the show and also set post-series too.