You agreed to have houseguests over the holidays. What were you thinking?

The idea is to keep chaos at a minimum this time of year. Having other people in your home, even ones you love, is only going to make things crazier. It's human nature to feel ambivalent about holiday visitors -- the traditional tug between enjoying having friends and family around and not wanting the extra work.

Well, first of all, pat yourself on the back.

"It's a great act of mercy and love to have people staying with you this time of year," says manners expert Letitia Baldrige. "The holidays are fraught with stress, everyone is sick with the flu. You're a hero for having them."

Baldrige knows what can go wrong. She once had houseguests who came on the wrong day, which wouldn't have mattered so much except that she was throwing a large party in their honor. When they didn't show up, she called to see where they were.

"They were just sitting down to a macaroni dinner," she recalls. "And they were a 1 1/2 -hour plane ride away."

Her party went on as planned, but the guests of honor didn't get there until the next day.

"Go over the details of the visit," she advises. "And then go over them again."

That includes finding out exactly when your guests are coming and, just as important, when they're leaving. Although talking about the end of the visit before it begins may seem awkward, you'll feel better if you know.

One of the most frequently asked questions at the Web site www.etiquettegrrls.com is what to do about guests that don't leave, says Lesley Carlin, 28, one of the Gen-X twosome Etiquette Grrls and co-author of Things You Need to Be Told. Unfortunately, there's no easy answer.

There are other things to discuss in advance that will help make the visit go more smoothly. Be sure to tell your guests in detail what you're planning (a cocktail party, a trip to the skating rink) so they can pack the appropriate clothes.

If visitors are flying in, a considerate host will offer to pick them up at the airport, although you might want to find out which airport first.

"One thing people never realize is that we're not next door to Dulles. That's crucial," says Joy Munster, a psychiatric nurse who lives in Guilford. If possible, tell your guests about BWI before they buy their plane tickets.

Surprise, I'm vegetarian

Munster and her husband, Andrew, now in their mid-sixties, are from England and Australia respectively. They have plenty of houseguests from overseas, particularly this time of year. She usually ends up making the two-hour drive to Dulles, but manners mavens say it wouldn't be rude if she instead got them a reservation on a shuttle and paid for it.

The Munsters' latest experience would have less easygoing hosts running for cover. Their houseguest was a cello player who practiced at odd hours. He was also a vegetarian, which he didn't tell Joy until half an hour before she was about to serve an elaborate chicken cacciatore dinner. She shrugs it off --"There was plenty else for him to eat."

In fact, she has only one negative thing to say about her guest. "I was interested that a grown man would leave his room in such a mess," she muses.

If you don't have a laid-back temperament and don't know your houseguests well, it's best to ask up front about food preferences, pet allergies -- and maybe even whether your visitor is bringing a musical instrument.

"Ask as many questions as you can," says Peggy Post of the Emily Post Institute in Burlington, Vt. You should be willing to accommodate your guests if you love them: by not serving meat at a family dinner, or keeping your cat in another part of the house. But most hosts have a few things they aren't willing to compromise over.

Novelist Walker Percy once said he always stayed in hotels when visiting friends because he didn't like other people's house rules.

We all have them, and it's best to let your guests know yours immediately.

Maybe you don't allow smoking in your home. Maybe you aren't comfortable having unmarried couples staying in the same bedroom, although many of us, including Munster, have given up on this one. One of her recent guests asked if she wanted him and his girlfriend to stay in separate rooms.

"Even three years ago I would have said yes," she admits ruefully. "These days I think you have to accept it whether you want to or not."

That was alarming

The most successful visits will happen when you find the right balance between what you can live with and what makes your guests feel at home. It's easy to suggest, even without meaning to, that having them there is making your life more complicated.

Vic Carter, the WJZ-TV news anchor, loves to entertain family and friends. As easygoing as he is, though, he's had his share of houseguest glitches. Once a friend visiting Carter's home in Howard County didn't tell his host he had breathing problems. In the middle of the night he woke up and suddenly needed fresh air. He didn't want to disturb anyone so he tried to figure out the alarm system on his own, with predictable results.

"Communication is most important to keep stress levels low," says Carter, which is one way to look at the chaos that ensued. The alarm went off, the Carters' phone line cut off, and he was lucky to be able to head off the police before they arrived.

Carter likes to quote his mother, who always said there were never any strangers in their home. He says he feels the same way. This gives him the comfort level to let his guests be self-sufficient, which is important with his schedule.

"It goes back to treating them like family," he says. "Always let your guests know how you operate in advance and what the expectations are. Make suggestions on what they can do on their own."

A good host might have a guide book of Baltimore on hand, for instance, or tickets to some local event when he isn't available. He doesn't, though, over-schedule his visitors, who need their downtime too.

That's true even when you're available.

"You don't need to plan every minute of a guest's time, which is the initial impulse," says Etiquette Grrls' Carlin. "Your guests are coming to spend time with you. They don't need to feel like you're their tour guide."

But if there are kids involved, as there often are this time of year, scheduling is a good thing. Get your tickets to the Harry Potter movie or the Nutcracker well in advance.

Nancy and Larry Rosenberg, who live in Greenspring Valley, had two adults and five children staying with them over Thanksgiving. Nancy, 45, made lists and prepared early. Several weeks in advance she tracked down the bed linens she would need and stocked up on kid-friendly foods. Other than the holiday dinner, she kept meals simple. (If you don't, you can end up feeling like a short order cook.) Breakfasts were served "dormitory-style" by setting up an assortment of cereals, bagels and drinks on the counter for people to help themselves as they woke up. Lunches were usually eaten out.

Even so, she says, "It's a project, no doubt about that."

You need to get on with your own life, but you also want to make your guests feel important. "Hopefully, it's sincere," says Peggy Post. Start by making the guest room inviting, with fresh flowers, an extra pillow, a bathroom glass. Have some little luxuries available, such as French hand soap. Show your guests "the lay of the land" when they arrive, Post continues. "Make them feel at home by saying, 'Please help yourself to anything in the fridge.' Try to anticipate what they need. If they get up early, show them where the coffee is."

Most important, says Nancy Rosenberg's husband Larry, have fun, even though it's a stressful time of year.

"So many people tense up," he says, "We find it relaxing. Don't let it change your routine. Or if it does, let it change it for the better."

If you're the guest

Maybe this holiday season you'll be staying in someone else's house. Here are some tips for making sure you'll be invited back:

* Bring a house gift. It doesn't have to be large.

* Pitch in with the chores.

* Keep your kids in check, particularly if your hosts don't have children.

* Be sensitive about your hosts' schedule and work around it.

* Arrange your own transportation. Don't expect to be ferried around.

* Offer to take your hosts out to dinner.

* If you're a smoker and your hosts aren't, smoke outside. They may be too polite to ask you.

* Keep your room neat and the bed made throughout the visit.

* Before you leave, strip the sheets off and remake the bed with the spread.

* Write a gracious thank you note promptly after your visit.