This is a great question.
If you adore classic sci-fi, I'd suggest starting with the JJ-verse movies, then watching TOS, TOS movies, etc. (or possibly reverse that).
If you're more into serialized, long-narrative story arcs, then I'd suggest starting with DS9.
However, DS9 is so rich and complex, and has such an epic finale, that for me, it is best savoured as the grand finale of your years of Trek viewing.
From my own experience, as a young lad, I very much loved the TOS movies (sans TMP), TNG, and TNG movies. This naturally flowed into watching VOY. Then I took a long break from Trek (in terms of truly exploring Trek outside of these afore-mentioned series) and, years later and hungry for more Trek, I finally came back and thoroughly enjoyed TOS, ENT, and DS9. I'm still warming up to TAS, as it is definitely the black sheep of the franchise. I've always loved all Trek. Now I appreciate each series even more. But the TOS movies, TNG, and TNG movies were definitely a great foundation to build from (and while not my experience, I'd definitely now include the JJ-verse movies in there as well).
Hopefully this helps. As far as literature, I think that is best enjoyed by those that have already assimilated all of the visual Trek and are yearning for more. As I understand it, the stories are largely built off of an assumption that you already know the characters and their on-screen adventures. For me, personally, the best literature I can recommend would be guidebooks that supplement the viewing experience, such as technical manuals, star chart/stellar cartography books, etc. that really help flesh out the universe-building aspect of Trek, which keeps it (mostly) all neatly tied together. You may become interested in the different Trek alien cultures, weapons and technology, starship designs, territories of space, etc.
Anyway, sorry to ramble on, but as a quick reference, here ya go:
TOS: The Original Series
TAS: The Animated Series
(TOS movies: TMP The Motion Picture, TWoK The Wrath of Khan, TSFS The Search For Spock, TVH The Voyage Home, TFF The Final Frontier, TUC The Undiscovered Country)
TNG: The Next Generation
(TNG movies: GEN Generations, FC First Contact, INS Insurrection, NEM Nemesis)
DS9: Deep Space Nine
VOY: Voyager
ENT: Enterprise
JJ-verse: post-2008 films directed by J.J. Abrams (ST09 Star Trek, STID Star Trek Into Darkness, STB Star Trek Beyond)