A good lie (story) always has a basis in fact. Why invent everything when someone else has done the work for you? You can pick and choose what you need to steal based on the needs of your particular work.
For Fantasy —
Most of the stuff you will want here is located in pre-mechanized historical warfare. The internal combustion engine changed the art of war in fundamental ways, even when horses were still being used (as late as WWII, believe it or not). Here are some excellent sources…
Hans Delbruck – In addition to being an amazing military historian, Delbruck was also an officer in the Prussian cavalry (when that still meant horses and not tanks). If he looks at a hill and states cavalry could not get up it under fire, believe him. There’s a collection of his history books that have been translated to English that are amazing resources. Warfare in Antiquity (scanned, not all chapters) is also available in print for pretty reasonable prices if you look around.
Charles Oman – Another amazing historian, who analyzed many less-famous battles (thus suitable for serial-number-removal and repurposing as your fantasy battle!) His magnum opus is available as a free ebook.
For Science Fiction—
We don’t have a lot to work with here, unfortunately. Submarine warfare gives some of the working restrictions, but a space battle will have MUCH better detection capabilities (even by Mark I Eyeball). The next best option are long-range naval battles of WWII vintage. Also note drone warfare as practiced in the most recent Iraq war and ongoing operations in Afghanistan. As the recent intercept of a drone by Iran showed, anything that flies by radio control can be taken over by radio control, so perhaps the day of the dashing fighter pilot isn’t over yet. Bear in mind that while energy weapons are cool, they also (duh) take a lot of energy that the ship in question might not have in sufficient quantities. The current US Navy electric rail gun prototype still uses a solid projectile, and a metric buttload of electricity to launch.