When you go in timeline order with Star Trek, you star with Enterprise books.
By the Book
What Price Honor?
Age of the Empress (Mirror Universe 1 Glass Empires)
The Good That Men Do
Now you move away from Enterprise into other stuff.
Starfleet: Year One
Now we go onto some TOS.
Enterprise : The First Adventure
Mere Anarchy #1: Things Fall Apart (TOS eBook)
My Brother’s Keeper: Republic
My Brother’s Keeper: Constitution
My Brother’s Keeper: Enterprise
And now we move onto Vanguard.
Summon the Thunder
All of the listed books are in timeline order.