(MONEY Magazine) – Pick your spot. Most villas (by which we mean freestanding, single-family country houses that you can rent) outside the U.S. are in Europe, Mexico and the Caribbean, with the most popular summer rentals in Italy and France. For the best deals in 1991, though, consider Portugal's south coast, the Algarve, where a three-bedroom seaside villa with pool and maid service costs about $2,100 to $2,800 a week in peak season. Other inexpensive houses can be had in Jamaica and western Austria -- a bargain for skiers. A chalet for six would cost as little as $840 a week in January in the Vorarlberg province, for < example -- less than half what you might pay in the more trendy province of Arlberg. If you fancy a fully staffed villa (cook, housekeeper, maid service and so on), focus on Mexico and the Caribbean, where labor costs are cheap (from $15 to $25 a day for a cook in St. Lucia, for example). -- Time your visit. High season in Mexico and the Caribbean is Dec. 15 through April 15. In Europe (excluding ski resorts), it's generally June through September, with July and August the busiest months. But for value consider the off-season, when you can save 20% to 50% on rent and avoid crowds too. ''Most places are just as beautiful in April and October,'' says Howard Isaacs, editor of Italian Traveler newsletter (P.O. Box 32, Livingston, N.J. 07039; 201-535-6572; $52 for 12 issues a year). -- Plan early. Start your villa search at least nine months before you want to go. ''Most of the best villas in the Algarve are booked by November for the following summer,'' notes Claire Packman of At Home Abroad, a rental agency in New York City. Nearly all European villas require that you book a minimum of two to four weeks in peak season; those in Mexico and the Caribbean usually require one week. Also, most U.S. agencies ask you to pay 30% to 60% of the rental cost when you first sign up, and the balance a month or two before you depart. But don't grumble. If the dollar is falling, as it has this year, you might come out ahead by paying earlier when the exchange rate is more favorable. -- Find a reputable, energetic agent. Interview several, asking such questions as: How long have you been in business? How recently have you inspected the properties you recommend? Do you have recent color photos of the house? Is it on the beach/close to town/near a noisy highway/on a secluded, unpaved road? Are utilities, phone service, linens and the like included? Are there any servants? And ''the most crucial question: Is there knowledgeable English- speaking management nearby in case of problems?'' adds Peter Collard, editor of the Villa Report newsletter (P.O. Box 4960, Greenwich, Conn. 06830; 203-454-2100; $65 a year for six issues). Also, don't take working telephones for granted. Ask. -- Close the deal. Some agents require a refundable damage deposit of up to 25% in advance, above the rental fee, plus a registration or administration fee, and fees for ''extras'' like maid service, bed linens and other amenities. In France, for example, where bedding often is not supplied, linens will cost an additional $25 or so a week per bed. Still, ''never send an agent any money until he or she has confirmed all verbal promises in writing,'' warns Collard. Those promises should include the rental rate, a description of the villa with photograph and the agency's policy on refunds in case you have to cancel. You might also want to take out cancellation insurance, such as the policy offered by Travel Guard (800-826-1300). It costs from 4.5% to 5.5% of your villa rental and covers cancellations owing to injury, sickness or death of any family member and certain other emergencies -- such as if a hurricane blows the roof off your idyllic, palm-shaded Caribbean retreat.