Every Saturday and Sunday afternoon my family piles into our red Oldsmobile station wagon and heads for the Beltway, looking for the homes of unsuspecting friends and relatives to visit. It's not that we have nothing to do at home; it's that we are not welcome there from 2 to 5 on weekends.

We are trying to sell our house, and we have been told in polite but firm tones that our presence is not appreciated there while real estate people, along with (hopefully) potential buyers, are looking it over.

Having one's home for sale is not a pleasant experience. Children see usually calm and patient parents rival the Incredible Hulk when an agent announces that he is bringing four clients by in 15 minutes.

Not only do we have an open house on Saturdays and Sundays, we have our house on "lock box." This means there is a box attached to our front door with our house key in it. Agents -- members of the Montgomery County Board of Realtors who put up $100 bond -- can purchase a key to open the box and bring visitors any time during the day. They are supposed to call first, but some times cannot reach me. Surprise:

Selling one's home and buying another is an emotional time for both buyers and sellers; it usually involves the biggest financial transaction in most people's lifetime. It brings out the best and the worst in people.

Since the For Sale sign went up in front of the house I have noticed subtle changes in our daily routine. For instance, I no longer take a pick-me-up shower late in the afternoon for fear I might be greeted by a crowd as I emerge. It no longer confounds me to see cars drive slowly by the house, then turn around and drive by in the other direction. (At first I thought we were being watched by burglars, or at least the CIA.) And when I hear a loud knock on the front door I usually know who it is: another agent with clients in tow.

Some people get carried away when their house is on the market. One mother I know became so nervous about keeping her house neat that she refused to allow any of her son's playmates in for the entire time -- seven months -- her house was for sale. Another mother insisted that her family eat off paper plates for five months.

Because your house is such a reflection of who you are, any criticism is not taken lightly. I once had two real-estate agents walk through the house and criticize every detail we had worked on for seven years.

Our pale blue wall-to-wall carpeting was all wrong. "What people want now," they sniffed, "are bare floors where natural wood can be shown off."

The wallpaper that adorns most of our rooms and that I had painstakingly picked out a few years ago is passe. "What people want today are white walls where the trim and molding are on display."

And why hadn't we bothered to put in a first-floor powder room in our den? "Today people demand accessibility, and a bathroom on the first floor is a must."

One friend recalls a real-estate person who barged in on her early one morning and dismissed her house as "way took small," her kitchen "an awful color," her yard as "insufficient," and then said: "I've just the clients to show it to!"

Although most real-estate agents we have dealt with have been courteous and thoughtful, there are exceptions.

One Saturday I was greeted at the door by an agent and client who wanted to see the house "right away." When I told her my husband was in the shower upstairs and suggested she return later, she ignored my protests. She marched upstairs and stood right outside the bathroom where my husband was singing merrily away in the shower. She didn't, fortunately, stay long.

The final coup de grace to my ego: One real-estate agent offered to come by early and help me clean up.

Agents, of course, have their own nightmares.

Deane Maury, for example, of Stuart and Maury, Inc., Bethesda, has "enough stories to write a book" on his real-estate experiences, a business he has been in since 1956.

He's tried to rent a house where the previous tenants allegedly were kidnaped by the Mafia and never heard from again. He's sold a house for a couple in the midst of a divorce, but still living temporarily in the same quarters. Because they refused to talk to each other, he had to negotiate a contract while acting as a go-between.

One innocent -- so the story goes -- realtor was forced out of town when the woman whose house he was trying to sell ran screaming into the street that he was trying to attack her.

Finding the right buyer, say agents, is the easiest part of the transaction. Negotiating a contract and helping buyers secure financing in these difficult times is the most challenging.

Most sellers are shocked, as we were, to find that our house was not purchased the first day we put it on the market, when a few years ago it probably would have sold almost that quickly. Today -- it's no secret -- the combination of high inflation and high interest rates has brought the housing market to a virtual crawl.

But in spite of the odds, I refuse to become discouraged. Even though our home has been on the market for more weeks than we care to count, we still have faith that because of its condition and location we will sell it soon. Since each person who looks is a potential buyer, I will keep showing the house with the hope that today might be the day.

And I take heart in the knowledge that the buyer may be the person (or couple) you least suspect. Take this story from a friend:

One weekday a woman came with her agent to look at his house. After peering into less than half the rooms she turned to the agent and said: "Let's go, I've seen enough." My friend was hurt at what he thought was an extremely rude comment.

Two hours later, the same agent appeared at the door with a signed contract from the client who had seen enough.

EPILOGUE: Free-lance writer Marie Wood, Bethesda, sold her house after 3 1/2 months on the market.