I remember first reading "Spock Must Die!" years ago, and I've never looked at the transporter the same way since.
I believe tha Blish worked from rough scripts when he wrote some of the episode adaptations, mostly those that appeared in the first 3 or 4 volumes. I think that's why some of those varied significantly from the aired versions that we are all familiar with - "The Doomsday Machine" being a prime example. The later volumes are quite a bit closer to the TV versions.
"Mudd's Angels" by Blish and J.A. Lawrence (she was his wife who helped complete the adaptations after Blish passed away during the writing of Star Trek 12) was the very first ST novel I ever read. It includes the two Mudd episodes from TOS, significantly expanded, plus a rather entertaining (but silly) sequel to "I, Mudd" called "The Business, as Usual, During Altercations" - quite fun to read as long as you don't take it seriously.
The Star Trek Log series by Alan Dean Foster was also pretty cool, especially Star Trek Log 10 which turned "The Slaver Weapon" into a full-length novel - it's still one of my favorite early ST books.