Alan Dean Foster was the very first Trek novel writer. waaaay back in the 60s.
Ehm, no? His TAS adaptions (he didn't do any original Trek stuff) started to be published in 1974. There were two writers before him:
James Blish: TOS adaptions from 1967 onwards, Spock must Die (1970)
Mack Reynolds: Mission to Horatius (1968)
ETA: gh4chiefs beat me to it. Had to find my copy of Voyages of the Imagination first to verify the dates.
