If all else fails and you are in over your head, hire an electrician before you electrocute yourself. If this is a fairly new house, these are all circuits that have GFCI outlets or breakers somewhere. Find it and reset it. (they have 2 buttons in the middle, 1 to test and 1 to reset). Your breaker could also be bad. Test it with a volt meter. Are these on one circuit or separate circuits? There may be a junction box or a junction in a light/receptacle/switch box that may have a bad connection or the switch/receptacle may be bad. You have to trace it all out using your voltmeter.
Also wires can short and melt and not kick the breaker. Post back with what you find. There may be a few other things to look at but lets see what you find after this first.