Congratulations, and welcome to the scrum!
Water Heater, yup, gotta make sure that anode rod is present and working. The reason it is there is to prevent corrosion of the water tank itself (and the electric heater element, too).
If the water heater keeps tripping the breaker, you might need to replace the breaker. Every time it trips, it gets just a wee bit weaker, and after some number of trips, it will become too weak to withstand the current it was supposed to pass. Before you do that, however, you might stick an ammeter in the heater circuit to see just what it is drawing. It is possible the element is damaged and draws too much power. You would want to fix THAT first, if needed.
