Sorry Broady...its one of those subjects that everyone has their own prefered methods / products.
Breaking it down, you need something for the chain, general lubrication of pivots and perhaps cleaning.
The chain is the one that will ellicit loads of different choices...cycling specific oils, of which there are many depending on conditions,, engine oil, 3 in 1, chainsaw oil, etc etc.
Ive tried many, barring chainsaw oil. It never made much difference which one I used, I always got the same kind of mileage. Engine oil and perhaps 3 in 1 are very useable...but messy.
Ultimately, clean with a cloth, oil, wipe, wipe wipe the excess off.you only need to apply a drop of oil to each roller to allow it to make its way into the pins...the only place its really needed.
3 in 1 is probably fine for everything else, WD is ok for light lubing, cleaning mechs etc when conditions are cr@ppy, and then there is grease for overhauling hubs etc.
Almost any grease will do, but better greases are lighter yet durable and reduce friction... the cyclists arch enemy.
Clear as mud...if you think about it too much.