Erick, you won't find many street-level tactical lessons in the book (and no firearms lessons). I think you will find some strategic ones.
The police, especially Riverside Sheriff's Office, were clearly outgunned. The then-sheriff, who had apparently made significant improvements over his long tenure, did not seem especially interested in improving the agency's tactical response capability. While he made improvements in the aftermath of Norco, his initial statements seemed to endorse the status quo. As I recall, he remarked that his officers were as well trained and outfitted as any officers in California. I doubt that or else the LASD Special Enforcement Bureau would not have been brought in, but more importantly, perhaps someone should have been paying attention. That said, I wasn't yet an officer when this occurred so I may be looking back through a retiree's eyes.
Interoperability of radio equipment was very much an issue. Most RSO personnel did not have the state-wide inter-agency channel. Our slain brother arguably might have survived had he known the bad guys were set up to ambush him around a blind curve. Communication between RSO and California Highway Patrol largely depending on cops listening to scanner (the way my former agency was for many years with the county police) as well as loudspeakers and hand gestures.
Post-traumatic stress was a significant issue for officers in the incident. There was significant anger toward two of the first three officers on the scene by the one who was left behind when the other two bailed to head to the hospital. No criticism of them for doing that based on what happened, but it didn't appear blameless to the cop who perceived abandonment. RSO had no critical incident debriefing or stress management program back in the day.
This incident, like others in recent times, was an explosives incident. While the bad guys' distraction bombing largely failed. They didn't seem that bright, but home-made grenade launchers firing explosives a hundred yards seem intimidating as do the hand grenades.
Long guns rule. Many of the deputies deployed shotguns. We'd be better with slide guns today with tactical buckshot and extended magazines, but a single pellet from a slide gun dropped the driver of the get-away car. Likewise for the other side as a helicopter sustained damaged that put it out of the pursuit.
Marksmanship counts. The slain deputy made a long range shot with a .38 revolver at over double today's qualification ranges that significantly wounded a perpetrator. Leadership counts. The San Bernardino Sheriff's Office was led by a street-cop at heart who seemed to care about the real world more so than his counterpart in Riverside.
The book is not perfect, especially for gun bunnies like us, but it is worth a read.