Routines vary widely, but here's what I do in winter... (NB - these are my regular checks: obviously you check the functioning of your bike daily and rectify braking, lighting etc problems as soon as they happen!)
Daily -
Check tyres for flints.
Weekly -
Give the bike a once over for anything untoward.
Particularly check brakes.
Check and pump up tyres (to max pressure in my case).
Wipe chain and re-lube with an oil soaked cloth.
Clean and lube gears.
Quick (in my case) wipe over of frame.
Re-charge lights for coming week.
Clean reflectors.
I carry spare batteries for my lights, and as I run 2 front and back, there's always a back-up available.