The Next Generation Reading List is centered around the Post-Nemesis Series, which chronicles events following Star Trek: Nemesis. The A Time To... miniseries acts as a lead-in to these stories, as well as to the Titan series. Accordingly there are two good "jumping on points" below.
Besides the Post-Nemesis Series, many additional novels, short stories, comics, and audiobooks are
connected due to various references in other books, or to other books. These references are mentioned in the notes.
Other novels are connected by six crossover series: Invasion! (which is referenced several times in the Lit-verse), Day of Honor (which shares references with several things in the Lit-verse), Double Helix (which ties into the New Frontier series), The Captain's Table (which is thematically connected to the Lit-verse spanning Tales From the Captain's Table), Section 31 (which ties into the Deep Space Nine Post-Finale Series), and Gateways (which ties into the Deep Space Nine Post-Finale Series and the New Frontier series.)
Twelve other short stories or novellas are also connected: one from Enterprise Logs (which shares references among several connected novels), one from The Brave and the Bold duology (which ties into the Gorkon series), two from New Frontier: No Limits (which ties-in to the New Frontier series), six from Tales of the Dominion War (which ties into four Lit-verse series), and two from Seven Deadly Sins (which ties into two other Lit-verse series.)
Sixteen novels in other series crossover with The Next Generation: SCE: Many Splendors, New Frontier: House of Cards, SCE: The Belly of the Beast, Deep Space Nine: Avatar Book 1, Deep Space Nine: Avatar Book 2, SCE: The Art of the Deal, SCE: Remembrance of Things Past Book 1, SCE: Remembrance of Things Past Book 2, Titan: Taking Wing, Articles of the Federation, Department of Temporal Investigations: Watching the Clock, Typhon Pact: Rough Beasts of Empire, Prometheus: Fire With Fire, Prometheus: The Root of All Rage, Deep Space Nine: The Missing, and Prometheus: In the Heart of Chaos. Several comics are connected by the Telepathy War crossover event (which ties into the Starfleet Academy series.)
Also included are the stories from The Sky's the Limit and the Slings and Arrows miniseries (both of which contain stories which share references with the A Time To... series.) Various references in parts of the Wildstorm Star Trek Special, the DC Specials #2-3, Unlimited #1, #4, and #8, and the anthology New Worlds, New Civilizations connect The Next Generation stories from those works.
The storylines of McCoy, Spock, and Scotty transfer to The Next Generation storyline starting with their appearances in the series, and their later adventures are included here. Scotty's storyline transfers to the SCE series at the end of the Dominion War. The Titan series spins off several characters from The Next Generation onto the USS Titan, and those characters' storylines leave this list at that point. IDW Comics' line of The Next Generation mirror universe stories were eventually rebranded simply The Mirror War, but that series is included here.
In addition, there are a few The Next Generation novels which, along with many The Original Series novels, comprised the "Original Lit-verse" of the 1980s. This was a group of stories which were eventually linked together through references and shared characters. Closely connected to these books was the DC Comics series of the 1980s. Characters were sometimes shared between the two media.
Several "Original Lit-verse" novels have been referenced in the modern continuity, more or less linking both bodies of work, though of course with continuity difficulties. The numbering system of the "Original Lit-verse" included here is strictly chronological and did not originate from the authors' or editors' intent.
The earliest book eventually connected to the "Original Lit-verse" was
published in 1977. The continuity flourished throughout the 1980s under
editor Dave Stern. Around 1988, under the direction of Gene
Roddenberry and Richard Arnold, a push was made to cut back on shared
characters and references between novels. This was not a hard rule, and
references between books and between comics continued at a slower pace
through the mid 1990s under Stern and Kevin Ryan. I place the end of
this era, and the advent of the modern Lit-verse, around 1995/1996,
under editor John Ordover.
Dark blue denotes the primary narrative. Read these for the bare bones story. Light blue denotes the expanded storyline. Read any or all of these to go a bit deeper. Dark green denotes the Original Lit-verse. Light green denotes the DC Comics, which were interconnected with the Original Lit-verse novels. The grey denotes every other connected story, regardless of continuity.
As always, not every reference to every other story is mentioned, just the one I chose as most important to show the expanding Lit-verse web.