Details on how a Rover engine operates
 

Had trouble finding what I'm looking for and bet the forum can help (as usual). Is there a detailed breakdown of exactly how the engine operates? Ideally I'd like to make notes for how my '04 D2 4.6L V8 operates from start to finish.

For example: from turning the key a step by step guide of what each part does and where that's located in the vehicle. How the oil, coolant, air, radiator, pistons, transmission, driveline, and flux capacitor all work together in tandem to do what we need them to do.

I have zero experience in working on cars and am excited to learn. Although this is my first rover I know it's not the last!

That's a tall order! I've never seen one but the RAVE manual comes close, but at over a thousand pages, it should.

Haha my bad! Not looking to be an expert. Just a place to learn the basics - I'll check out rave manual

Maybe someone knows of a cliffs notes version online :)

All But Flux Capacitor
 

Rave has all/most of the info in the Workshop Manuals & Electrical Circuit Diagrams but requires some jumping around to put into story form. Helps to have had experience with other technical manuals and once a PDF file is open the search function is useful.

D2 Workshop Manual has a description/operation at the beginning of most sections and probably where you'd like to begin. Enjoy.

......

u-tube is filled with videos that will give you plenty of the basics you need to know.
maybe find yourself a couple interesting ones watch and then read the corresponding chapter RAVE after to find the LR specific differences.

Get a book on old Buick V8's, the Rover is not much different apart from the electrics.

The RAVE manual is a good place for things specific to the Discovery, but it's more suited to troubleshooting and maintenance or repair. It sounds like you'd benefit more from a basic explanation of internal combustion engines. If you don't understand how a lawn mower operates, there's not much point in focusing on Buick or Rover specifics.

Start with the basics of the 4-stroke "Otto" cycle. Check out "volumetric efficiency." Learn about multiple cylinder configurations (twins, fours, sixes, and V8's). Look at the different valve arrangements (side-valve, overhead valve, overhead cam, etc.). Study air/fuel mixtures, stoichiometric ratio, carburettor vs. fuel injection. Study ignition, learn how spark plugs and "points" work, a distributor, and then electronic ignition. Then learn about wet sump lubrication, pressurized cooling with coolant to air heat exchangers (radiator), and then gearboxes, automatic transmissions, transfercases, driveshafts, ring and pinion gears, differentials, axles....

As per binvanna's recommendation:
Animated Engines - Four stroke

Discovery Series 2 Engines - Dealer Training Video about Td5 and V8