Thanks for the replies.
1) Are any of the circuit breakers the AFCI or GFCI type which will have a test button? The dead circuit may reside on a breaker that has tripped.
2) If the breaker did not trip or no AFCI or no GFCI, then the problem is either an open or an open neutral wire. You will need a multi-meter to confirm which wire is an open. Once the open wire is confirmed, whether open hot or open neutral. Now you know what to look for by performing a visual inspection at the dead receptacles.
3) If the hot wire is good, it will show 120 volts from hot to ground which indicates that the problem is not a hot wire issue. If 0 volts from hot to neutral, then you know the problem is a neutral issue. Thus the reason to have a multi-meter to take voltage measurements.
4) Once the voltage measurements are confirmed, now you know what to visually look for. A visual inspection will be required in the 1st box that is closest to the electrical panel for that circuit. The circuit can be split in half and measurements can be taken in order to narrow down the problem and isolate it.
5) Keep in mind that the circuit can easily tandem thru other known working boxes (receptacles, light fixtures, switches) from other circuits. All depends upon how the original electrician wired up the circuit.