If you can afford it, get comfortable with delegating. I also have a two and four year old. I have someone come over and do the dishes, laundry, pick up the toys and clean the house a few times a week. It has been a huge relief and now I get to spend way more one on one time teaching and playing with them. I can't say I understand what it's like to be a working Father. I'm a stay at home Mom with with a debilitating disease that can take up a lot of time and energy.
A good motto with kids is, if you can afford it outsource it. Part of what the US does not do well is provide a basic level of outsourcing (day care) to those who cannot afford to.
