I, for one, can vouch for the amount of preparation a vacation takes, from researching the destination to researching tour operators and finally making final itinerary decisions ... which for some reason don't always stay final. But that's another story.
This post is about preparing your house for your vacation. We have our own checklist that has evolved over time. The following is a bit more general and will apply, in most cases, whether you are going away for a few days or a few months.
If you'll be gone during the summer months, raise the house temperature to 78 degrees. Every degree you raise the thermostat will save you about 2 percent on your heating costs.
If you have a pool, continue to run it so the pool doesn't develop algae and turn green. Check the settings to make sure they are where you want them. If you'll be gone long-term, ask a friend or neighbor to stop by and monitor things. If you have a spa, you can turn off the heat.
Turn off water at the main shut-off valve unless you've got household items that require water on a regular basis such as an automatic sprinkler system. If you'll be gone more than a month, as a friend or neighbor to turn on the water and run the faucets at least once a month. This helps prevent sewer gas from etering the house and can keep parts of plumbing fixtures from drying out.
If your water heater has a "vacation mode" setting, use it.
Pour a half cup of chlorine into the bowl to reduce bacteria which can cause stains.
Put inside lights on variable timers.
Throw out perishables (or pass along) like milk which may expire while you are gone. If you will be absent for along time, generally clean out the refrigerator. If you'll be leaving it running while away, fill it with bottles of water so it will run more efficiently.