My spot cleans consist of changing tidy mats (can be bought from guinea pig accessory merchants) whenever they feel moist to the touch. I always feel for wet spots when I'm doing daily sweepings. My guineas have favorite spots to pee, so this extends the life of the main fleece underneath.
I may be excessive, but I normally change out their fleece everyday, though sometimes I do it every other day, with spot cleans in between. I have their fleece on top of puppy pads, and i normally only change out the puppy pads once every 5 days or so.
I do a full cleaning with changing fleece and towels/u-haul pads once a week, change their potty pads once a day and do a quick clean up twice a day when I do their veggies and water with a wet/dry shop vac.