Check your basement frequently for any moisture. Mold spores develop in moist areas and can become a health hazard.

If you have any shrubs or bushes that contact the house trim them back. Insects such as carpenter ants often use the branches that are touching your home to gain initial access to your home.

Always replace your furnace filter at least once/month throughout the year. During the winter you may even want to consider changing it more often since it is running much more. Also, if you are having any work done in your home such as a remodeling job or something similar, you should make sure you are changing the filter quite often because of all of the dust that is being ****ed in through the cold air returns. Also, make sure you have your furnace and/or central air unit's) maintained every year, or every other year if the unit's) is quite new, by a licensed professional. This will allow the units to run smoothly and most likely last a lot longer.

If you own a home with cedar siding, be sure to have it painted every 4-5 years. If your home has a side of the house that is directly in the sun for the majority of the day, then you may want to paint it more often. The paint will protect your siding, as well as give it some nice curb appeal.

Make sure that your gutters are in good shape and cleaned out regularly.

Caulk around doors and windows to prevent moisture from entering your house. This will also save on heating/cooling costs.

Once a year, get up on the roof and take a look at the shingles or tiles. Look at the roofing under any missing shingles. If needed, replace a portion of the roofing and/or shingles.

And remember that roofs have a life of between 12 and 25 years. Re-roofing before any water damage takes hold can save thousands of dollars. If your roof is too steep, or you don't have the time, pay a roofer to inspect it. If he says it needs replacing, always get a second opinion and bids.