Planning a home improvement project? There is a lot you need to know before diving in.

Action Line has heard endless horror stories from homeowners who invested thousands into a seemingly straightforward repair or upgrade that somehow devolved into a nightmare. The surprising part is that, most of the time, the problem boils down to what the homeowner didn't do.

In this Mini-Guide, we'll outline some simple but direly important steps you need to take to protect your investment -- and your sanity.

CHOOSING A CONTRACTOR

• References: We can't emphasize enough the importance of good ole recommendations. While going on someone else's good experience is not enough, it is easily half the battle. Ask close friends, trusted neighbors and family who they hired and whether they were happy with the work, service, price and communication with the contractor.

In addition to word-of-mouth references, find out how other homeowners graded particular contractors in your area at www.AngiesList.com. Subscriptions are month-to-month ($22.50 the first month, $7.50 additional months), annual ($59 plus $15 sign-up fee) or longer. You can also call Angie's List, toll-free, at 866-887-6166.

Complaints lodged with the Better Business Bureau of South Florida (www.bbb.org; 561-842-1918) can also provide some insight on a company's dealings. Scrutinize the nature of complaints and a company's resolution history.

• Get multiple estimates: Do not hire the first contractor that comes along. Get at least three estimates from different companies, more for a major job such as an addition. Ask what's included in the price and get it in writing. This is also a good time to get the contractor's license number and ask whether he or she is licensed by the county or state. (If they can't give you one, send them home on the spot.)

• Check legal status: The majority of construction jobs -- roofing, shutters, electrical, plumbing, to name a few -- must be done by a licensed professional. Unlicensed contracting is a criminal offense. To ensure accountability, companies operate under the license of one person, or "qualifier," usually the owner or another principal of the company.

Licensing can come from the county or state you reside in and requires that the qualifier has demonstrated experience and passed a test in order to be qualified by the licensing authority to do specific kind of work, within the authority's jurisdiction. For example, contractors licensed only in Miami-Dade can't work in Broward and vice-versa; state-licensed contractors can work throughout the state.

Perhaps the single most important thing you do before hiring contractors will be verifying his or her licensing status and official complaint history. This can be done online or by phone:

In Miami-Dade, the Building Code Compliance Office is the licensing authority for construction contractors; www.miamidade.gov/buildingcode, 305-375-2901. In Broward, check with Building Code Services: www.broward.org/building, 954-765-5075. Contractors licensed by the state are under the authority of the Department of Business and Professional Regulation, based in Tallahassee; www.myflorida.com/dbpr, 850-487-1395.

Note: In Action Line's experience, county licensing authorities have proven much faster and more effective at addressing and resolving homeowner complaints than the state DBPR. Most large companies are licensed by the DBPR, but because it is painfully slow to take action when something goes wrong, we recommend you take that into consideration when choosing a contractor.