Pickup and pot essentially form a sort of low pass filter. The higher the resistance is on the pot the higher the cut point will be (as the increased resistance of the coil at higher frequency is less significant).
So generally you’ll have that a higher resistance on the pots will result in more overtones being preserved in your signal, while a lower resistance pot will sound "warmer" by taking way such overtones.
Some things to keep in mind: Humbuckers do cause high frequency loss by themselves, so often they are paired with higher resistance potentiometers. As acoustic guitar will necessarily have some dampening on the strings, which affects high frequencies more than low frequencies. So you should expect less high frequency output in the first place.
Also if you add a tone pot circuit you are increasing this high frequency loss. With tone and volume pot each 500kΩ at "pass through" this will thus look like 500kΩ + 500kΩ in parallel to ground, which results in a resistance of 1 / (1/500 + 1/500) kΩ = 500/2 kΩ = 250kΩ. Thus if you plan to use a volume + tone circuit it is reasonable to use twice the resistance you’d go for else.
Also the tone pot will allow you to add a low pass at your liking, so you might want to go for brighter to have the option.
So it makes sense that the single coil diagram as 250kΩ, while for the humbucker you might use 500kΩ. When adding tone you might even think about getting 1000kΩ (or 1 MΩ), especially if the pickup is already rather dark on the acoustic guitar.
If you want to you can test this out during the installation: Simply get yourself a pair of resistors at 250kΩ, 500kΩ and 1MΩ (these are very cheap, also you can probably ask any electronics repair workshop for some spare resistors (if not you can also just buy 250kΩ resistors and put them in series to get the higher values. Or just buy 1MΩ and put them in parallel to get lower values. Or whatever). Then bridge two resistors to ground (maybe add a capacitor for one to make it really realistic, if you leave out the capacitor you could also just use single resistors at 125kΩ, 250kΩ, 500kΩ). This should then simulate the behaviour with both pots turned all the way up without having to buy multiple more expensive capacitors. If this sounds too bright or harsh for you, go for a lower resistance, if it is too dark go higher.
Now: What do you need, and how do you wire it? You need the pickup. I’m assuming you know which cable of your pickup is hot and which is ground. You need two pots, probably 500kΩ, maybe also 1MΩ, depending on whether you like the sound. Make sure these pots scales logarithmically and not linearly, because else you’d get the most action in the lowest portion of the pot (our hearing is not linear!). Get a small capacitor of a size of your liking (10-22nF, the higher the capacity the lower the cut frequency, so more treble cut). In fact, get multiple capacitors, then you can try some options. You need a socket. And you need wire. If you get wire in two colors you can color code ground and hot phase.
The socket has two connectors, one that goes to the tip and one that goes to the shaft of the jack. The shaft will be ground!
So first thing: The ground of the socket should be connected to the ground of the pickup, the case of each potentiometer and the third pin of the volume potentiometer. The second pin of the tone pot should be connected to ground through the capacitor.
The hot cable of the pickup should be connected in parallel to the first pin of both volume and tone pot. The second pin of the volume pot should be connected to the tip connector of the socket.
This is something like the usual way of how to wire these things, but there are alternatives.
You will also need to think about where you are going to mount the socket and the pots. This should be done in a place you can reach through the soundhole, and if you have potentiometers in a place you can reach well. You will need a drill for installing these. Assemble the circuit outside of the guitar and then try to install everything through the soundhole.
