ooh, that's difficult.
The first book by Paul Gilcrist is a great read with bunch of great photos and even better stories. If you read a lot of US Naval History, you might recognize the name of the author, if you don't he was a Naval Aviator in from the 50's through the 80s. He was in the Pentagon during the F-14 acquisition and support processes. He uses his first hand knowledge, as well as a bunch of second hand stories to craft an oral history of the Tomcat through the early 90s. A lot of it is "Stories from Baseball", but it's all entertaining, and it offers a pretty good picture into why the F-14 never got the upgrades that were planned and why it was always making do.
The second is a technical history of the Tomcat that offers a pretty good explanation of technical systems while interspersing those with testimonials from serving Tomcat pilots. I'd honestly lean towards this one.
The third is... I have no idea how it got published. It's the closest thing to a NAVAIR manual I've seen in print (that isn't the actual NAVAIR which is out there ) , and it was printing in like 1976. There was talk the author almost got indicted on illegal export charges. It offers a pretty good technical rundown of a 1970s vintage F-14, with some neat diagrams on what various sensors display in certain modes.
I'd go with the first if you want a better understanding on the history of the Tomcat and Tomcat community, the second if you want a history of the Tomcat and a more technical explanation. and the third if you want a high level brief on know how a Block 90 Tomcat ticks.