Inside Star Trek: The Real Story by Herb Solow and Bob Justman is a must read memoir about the making of the original series.
This & Solow's "Star Trek Sketchbook" are probably the most insightful books into the making of TOS. And David Gerrolds' "Making of Star Trek" & "The Trouble with Tribbles"- excellent!
I find most of the autobiography books disappointing. The actors don't seem to remember a lot. They recite a lot of what they've said in interviews 100x before. Or the history we're already aware of. I want the little details of their experiences on set, and rare pics.
Well, then have you read "Chekov's Enterprise"? I recently read it for the first time and think it has the qualities you want.
It's basically a diary of Walter Koenig's experience of making TMP and it's successful as a day in the life of a Star Trek supporting cast regular on the set.
HIGHLY recommended.
In fact, you should hit eBay right now and get yourself a copy. RIGHT NOW.