You want an exhaustive list?
Okay, here's a possible answer to your questions above.
Thrawn gave you the most important, but if you want to know what else is connected, I'll give a list of most of the post-series stories that form part of, or tie into, the mainstream continuity. This is deliberately extensive, basically overkill. Keep in mind you don't
have to read anything (well, starting a particular series half way might be a bad idea

. If you want to know what in particular to read, the others can give pointers. But here's the big one. In more-or-less in-universe chronological order:
The Battle of Betazed
Tales of the Dominion War
Mirror Universe: Obsidian Alliances
The Left Hand of Destiny,
book one
The Left Hand of Destiny,
book two
Gemworld,
book one
Gemworld,
book two
Diplomatic Implausibility
A Stitch in Time
SCE omnibus: Have Tech, Will Travel
Avatar,
book one
Avatar,
book two
SCE omnibus: Miracle Workers
Section 31: Abyss
Demons of Air and Darkness
SCE omnibus: Some Assembly Required
Twilight
The Brave and the Bold,
book two
SCE omnibus: No Surrender
SCE omnibus: Foundations
SCE omnibus: Wildfire
This Gray Spirit
Cathedral
A Good Day to Die
SCE omnibus: Breakdowns
Lesser Evil
Honour Bound
Rising Son
Corps of Engineers omnibus: Aftermath
Unity
Enemy Territory
Worlds of DS9: Trill: Unjoined
Worlds of DS9: Bajor: Fragments and Omens
Corps of Engineers omnibus: Grand Designs
Worlds of DS9: Andor: Paradigm
A Burning House
Corps of Engineers omnibus: Creative Couplings
Worlds of DS9: Ferenginar: Satisfaction Is Not Guaranteed
Mirror Universe anthology: Shards and Shadows
Worlds of DS9: Cardassia: The Lotus Flower
Corps of Engineers omnibus: Wounds
The Genesis Wave,
book one
The Genesis Wave,
book two
Worlds of DS9: Dominion: Olympus Descending
Genesis Force
Warpath
Fearful Symmetry
Vulcan's Soul: Exodus
The Soul Key
Corps of Engineers omnibus: Out of the Cocoon
Vulcan’s Soul: Exiles
Vulcan’s Soul: Epiphany
Corps of Engineers omnibus: What’s Past
Voyager: Homecoming
Voyager: The Father Shore
The Never-Ending Sacrifice
Voyager: Old Wounds
Voyager: Enemy of my Enemy
A Time to Be Born
A Time to Die
A Time to Sow
A Time to Harvest
A Time to Love
A Time to Hate
A Time To Kill
A Time to Heal
A Time For War/A Time for Peace
Death in Winter
Titan: Taking Wing
Titan: The Red King
Resistance
Titan: Orion’s Hounds
Q and A
Titan: Sword of Damocles
Before Dishonour
Articles of the Federation
Greater Than the Sum
Destiny: Gods of Night
Destiny: Mere Mortals
Destiny: Lost Souls
A Singular Destiny
Losing the Peace
Voyager: Full Circle
Titan: Over a Torrent Sea
Voyager: Unworthy
Titan: Synthesis
Mirror Universe: Rise Like Lions
Voyager: Children of the Storm
Typhon Pact: Rough Beasts of Empire
DTI: Watching the Clock
Typhon Pact: Zero Sum Game
Typhon Pact: Seize the Fire
Typhon Pact: Paths of Disharmony
Indistinguishable From Magic
If you want to be even more exhaustive, the above books sometimes reference the events of novels set earlier than the series. You might, if you're being a completist here, want to get the Lost Era series and a few books set alongside it:
The Sundered
Serpents Among the Ruins
Terok Nor: Day of the Vipers
The Art of the Impossible
Well of Souls
Vulcan's Heart
Terok Nor: Night of the Wolves
Deny Thy Father
Catalyst of Sorrows
The Buried Age
Terok Nor: Dawn of the Eagles.
And you might want the Vanguard series too, set before the above novels, during the TOS series.
I
think that's more or less an exhaustive list....