Useful Links

http://www.wikihow.com/Flush-a-Water-Heater
Water heaters should be flushed every one to three years depending on the model and water source. This helps to control the buildup of mineral deposits. Your water heater will operate more efficiently and this usually will extend the life of the heater.

http://www.houselogic.com/home-advice/heating-cooling/hvac-maintenance/#.
You can prolong the life and increase the efficiency of your system if you follow this simple maintenance plan.

http://www.houselogic.com/home-advice/roofing-gutters-siding/wood-siding-care-and-maintenance/
Wood siding is one of the most beautiful of all types of siding—and one of the most expensive. If you’d like to avoid repairs that could cost thousands of dollars, and you’d like to keep your clapboard, shingles, or board-and-batten lasting for decades, regular upkeep and maintenance is critical.