If you like David Weber's work, Check out his collaboration series with John Ringo. Ringo also has several series and trilogies/quadrilogies.

Loosely related to finding new books to read, I have another question.

Does anybody else sometimes start a series, stall in the middle and then want to go back to it later? Many years later? And then, how do you refresh your mind on what's happened in the previous books?

Case in point: I struggled with Clan of the Cave Bear through several starts and stops, then one time I got excited about it and read it through. Then burned through the next two, Valley of Horses and The Mammoth Hunters. Then stalled again about 10% of the way through Plains of Passage. Now there are even two more after Plains. But the last time I touched Plains was well over a decade ago. Maybe two decades.

Is there like a "Cliff Notes for Novels" site somewhere that I might be able to re-learn what's happened in the series up to the point where I stopped, so I can pick it up again without re-reading from the beginning? Some summaries, but more detailed than what you get in the sales blurbs for the books on Amazon?

p.s. - I did look at the Cliff Notes website, but searching for these books didn't turn up anything. There are book plot summaries on Wikipedia, but I was hoping for a little more detail than those provide.

Because I am a former Air Force guy, I would suggest Dale Brown - "Flight of the Old Dog" and his subsequent books.

I don't usually have that problem but with the David Weber series it's grown to the point that I start with the original "On Basilisk Station" when a new book comes out.

+1

H. Beam Piper Paratime/Lord Kalvan of otherwhen
RH Heinlein Tunnel in the sky, Glory Road, anything you can find, including the "Heinlein Juveniles".

Oddly enough, western novels by Donald Hamilton, Loren Estleman, or Louis L'Amour hit the same notes for me: solid science, natural history, cultural history, interesting weapons and compelling landscapes.
Sidenote: none of these authors had a character pick up a revolver that turns into a semi-auto later in the paragraph. Some authors do that. Makes me crazy.

That was my favorite as a kid!

Farnham's Freehold.