Q: I plan to sell my house soon. My husband has died and the house is just too big. We lived in the house for more than 30 years and it is difficult, both financially and emotionally, to sell it. I have discussed my situation with a real estate agent, who is eager to help me. What do I look for when selecting a real estate agent? What is the difference between an agent and a broker? What does "buying a listing" mean? What is a listing?

A: I could write a book in answering your questions, but let's start at the beginning. You have decided to sell your house. Do you have any idea what it is worth? Obviously, you do not want to sell at a low price, but you also do not want to set the price so high that potential buyers will be turned off.

One way to determine the market value of the house is to hire an appraiser, who will give you his/her best estimate. An appraisal will cost $300 to $500. While I usually do not recommend that sellers obtain an appraisal--because of the cost--in your case it may make sense.

You can also ask several real estate agents to evaluate your house. There is nothing wrong with soliciting several real estate companies before deciding which one to use. In fact, you should shop around. Each agent should be able to give you an estimate of market value.

Some people use their local property tax assessment as an indication of market value. You should not rely on that number because it often is considerably below the market value.

You asked about agents and brokers. An agent works for a broker, the only person who can earn a real estate commission. This is really a technical legal distinction, which should not be of concern to you.

However, you also asked about the concept of "buying a listing." This is a matter that should concern you.

When you finally pick the person you want to help you sell your house, you will have to sign a contract. That contract is called a "real estate listing." In effect, you will be authorizing the real estate broker-agent to list your house for sale. If the agent is successful, a commission will be earned.

However, there are some agents and brokers who are too eager to get a listing because they earn a commission if the house is sold--whether the buyer is brought in by the listing agent or some other agent (called the selling agent). Sometimes agents will inflate the value of your house to convince you that only they are capable of getting you top dollar. After you have signed the listing contract, however, you may suddenly realize that the listing price is too high; but by then you are stuck for the length of the listing contract.

This is known in the real estate trade as "buying a listing." How do you avoid this trap? That's where shopping around, and even getting your own independent appraisal, come in--before you sign any listing agreement. Both will help you be sure the listing price is realistic.

What should the real estate listing contract include? Keep in mind that the listing agreement form can be changed. You have the right to add and delete paragraphs to meet your needs. Here are some suggestions for items to be included in any listing agreement:

* "The commission will not be earned until and unless settlement actually takes place." The standard listing agreement states that a commission will be earned should the broker bring you a purchaser who has signed a real estate contract. But what happens if that buyer does not go to settlement? Without this proposed language, the agent could legally claim a commission, even though you have not sold your house.

* The listing should be for not more than 90 days. You can always extend the listing, but if you tie your house down for a long period and are dissatisfied with the agent, it will be difficult to terminate the listing agreement.

* Make sure that all terms are included in the listing agreement. These terms include such things as price, the amount of any points you agree to pay and any other seller concessions you are willing to make.

If there are certain items that will not convey with the house, they also must be included in the listing agreement. For example, if you want to take your favorite chandelier with you, you must advise the broker, in writing, at this early stage. You should understand that any item affixed to the house--such as light fixtures, mirrors, plumbing, etc.--are legally supposed to convey to your purchaser. Washers, driers and refrigerators generally convey, but not always. To be on the safe side, spell out your intentions in the listing agreement--and then again on the real estate contract when there is a potential purchaser.

* What will you pay the agent if your house is sold? Negotiate the commission before you sign the listing. Many agents will agree to sell your house for less than 6 percent so long as no other agents get involved in the transaction.

* Your decision on whether to allow a sign in front of your house. Will you allow the agent to hold open houses--and if so, how many per month? How often will the agent advertise the house? All of these are important items and must be included in the listing agreement.

You also should engage the services of a competent real estate lawyer, who will give you guidance throughout the process. The lawyer should review all documents that you sign--before you sign.

If you have children and if they are in the area, consult with them throughout the process. Maybe one of your children would like to buy the house to keep it in the family.

Selling a house should not be a complex process. However, there are too many players involved in the real estate game--and most of them are primarily looking out for themselves. Make sure that you have players who are on your team, and who will be working exclusively for you.

Kass is a Washington lawyer. For a free copy of the booklet "A Guide to Settlement on Your New Home," send a self-addressed stamped envelope to Benny L. Kass, Suite 1100, 1050 17th St. NW, Washington, D.C. 20036. Readers may also send questions to him at that address.