One small drop on each link of the chain (it doesn't take anywhere near as long to do as it sounds). Turn the pedals and shift up and down through all the gears a couple times to spread the lube around. Then wipe down again to remove any excess.

As said- one drop per link. SRAM chains with the power link makes this easy to keep track of.

I'll add a couple drops around the pulleys and and springs and joints. Wipe dry.

^Definitely do it after riding in the rain or anywhere dirty. Otherwise, it should be done maybe every couple weeks.

Depends on the nature of your lube. I use a wax-based lube (White Lightning, but they're probably all similar). My experience:

Petroleum-based lube disadvantages:
- dirt magnet
- hard to clean drivetrain components (need a solvent)

Petroleum-based lube advantage:
- single application lasts longer than wax

Wax-based lube disadvantage:
- single application doesn't last as long as oil

Wax-based lube advantages:
- drivetrain stays cleaner, longer
- cleaning drivetrain easier than oil

Cleaning and lubing is almost the same step with wax-based lube:

1. Backpedal while generously dripping wax lube on chain (you know it's enough if the chain drips just a bit after you stop).

2. Wipe excess off with shop rag. Use generous pressure in the vertical plane with multiple fingers to promote lube penetration into the rollers. Here's where you'll notice the dirt shedding property of a wax lube - the dirt will come off with the excess wax.

3. Clean the chain rings, cassette, and derailleur pulleys with a dry shop cloth. These parts do not need lube on the contact surfaces.

Needed less often:

4. Clean and grease (not oil or wax) the derailleur bearings.

Fortunately for me I have access to a steamcleaner so I just hose it all in lube and wipe off any excess. So once a week it gets steamcleaned and relubed and my gear is always quiet and and works super slick.