I'm home fulltime in the summers. My answer is, you learn to let a LOT of stuff go. You won't be a perfect parent, and you won't be a perfect housekeeper (well, not without paid help!), so you do what you can when you can. Sit him on the floor with a few of his favorite toys while you cook dinner or run dishes. Let him "help" you while you fold laundry.

We keep a loose schedule in the summers, dictated by the baby. Both girls set themselves loose routines by four months of age, which helped. But mainly I go with the flow during those times because I've realized that no matter how hard I work, the reward is only temporary at best. Everything gets REALLY messy again. And I do my work-related stuff while I'm at work, or at night after the girls are down for the night.