Watering needs to begin as soon as installation of your new sod has begun. One gallon of water the first hour is worth ten gallons the next day.
Water slowly enough to avoid run-off, but long enough to soak through the sod pad onto the ground below. This may be monitored by peaking under corners of the sod around this area. Pay special attention to exposed edges, as these are sometimes missed. These edges will also dry out faster so keep an eye on them. The best time to water is early morning or late afternoon.
This manner of watering will need to continue for at least two weeks. Frequency of watering will depend entirely upon air temperature and rainfall. During this time the area will be very soft so it is important to redirect foot traffic (human and pet) away from this area.
After two weeks, begin to lengthen the time between watering. After about three weeks, your sod should be rooted and able to fend for itself.
If your sod is installed in May or later, this area will need to be watched during the summer months for signs of drought stress which would require extra watering