American Express-- Travel-service offices are located in the Loop at 55 W. Monroe St. (tel. 312/541-5440) and across from the Virgin Megastore, at 605 N. Michigan Ave. (tel. 312/943-7840).

Area Codes-- The 312 area code applies to the Loop and the neighborhoods closest to it, including River North, North Michigan Avenue, and the Gold Coast. The code for the rest of the city is 773. Suburban area codes are 847 (north), 708 (west and southwest), and 630 (far west). You must dial "1" plus the area code for all telephone numbers, even if you are making a call within the same area code, except in area codes 773, 312, and 847.

Babysitters-- Check with the concierge or desk staff at your hotel, who are likely to maintain a list of reliable sitters with whom they have worked in the past. Many of the top hotels work with American ChildCare Service (tel. 312/644-7300), a state-licensed and insured babysitting service that can match you with a sitter. The sitters are required to pass background checks, provide multiple child-care references, and be trained in infant and child CPR. It's best to make a reservation 24 hours in advance; the office is open from 9am to 5pm. Rates are $17 per hour, with a 4-hour minimum.

Business Hours-- Shops generally keep normal business hours, 10am to 6pm Monday through Saturday. Most stores generally stay open late at least 1 evening a week. And certain businesses, such as bookstores, are almost always open during the evening hours all week. Most shops (other than in the Loop) are now open on Sunday as well, usually from noon to 5pm. Malls are generally open to 7pm and on Sunday as well. Banking hours in Chicago are normally from 9am (8am, in some cases) to 5pm Monday through Friday, with select banks remaining open later on specified afternoons and evenings.

Dentists-- The 24-hour Dental Referral Service (tel. 630/978-5745) can refer you to an area dentist. Your hotel concierge or desk staff may also keep a list of dentists.

Doctors-- In the event of a medical emergency, your best bet -- unless you have friends who can recommend a doctor -- is to rely on your hotel physician or go to the nearest hospital emergency room. Northwestern Memorial Hospital also has a Physician Referral Service (tel. 877/926-4664). See also "Hospitals" below.

Emergencies-- For fire or police emergencies, call tel. 911. This is a free call. The nonemergency phone number for the Chicago Police Department is tel. 311. The city of Chicago proclaims the following policy: "In emergency, dial 911 and a city ambulance will respond free of charge to the patient. The ambulance will take the patient to the nearest emergency room according to geographic location." If you desire a specific, nonpublic ambulance, call Chicago Ambulance (tel. 773/521-7777).

Hospitals-- The best hospital emergency room in Chicago is, by consensus, at Northwestern Memorial Hospital, 251 E. Huron St. (tel. 312/926-2000; www.nmh.org), which opened a state-of-the-art medical center right off North Michigan Avenue in the spring of 1999. The emergency department (tel. 312/926-5188 or 312/944-2358 for TDD access) is located at 251 E. Erie St. near Fairbanks Court. For an ambulance, dial tel. 911.

Internet Access-- Many Chicago hotels have business centers with computers available for guests' use. Computers with Internet access are also available to the public at the Harold Washington Library Center, 400 S. State St. (tel. 312/747-4300) and at the Internet cafe inside the Apple computer store, 679 N. Michigan Ave. (tel. 312/981-4104).

Liquor Laws-- Most bars and taverns have a 2am license, allowing them to stay open until 3am on Sunday (Sat night); some have a 4am license and may remain open until 5am on Sunday.

Newspapers & Magazines-- The Chicago Tribune (tel. 312/222-3232; www.chicagotribune.com) and the Chicago Sun-Times (tel. 312/321-3000; www.suntimes.com) are the two major dailies. The Chicago Reader (tel. 312/828-0350; www.chireader.com) is a free weekly that appears each Thursday, with all the current entertainment and cultural listings. Chicago Magazine (www.chicagomag.com) is a monthly that is widely read for its restaurant reviews. CS is a free lifestyle monthly that covers nightlife, dining, fashion, shopping, and other cultural pursuits. The Chicago Defender covers local and national news of interest to the African-American community. The Spanish-language La Raza (www.laraza.com) reports on stories from a Latino point of view. Windy City Times (www.outlineschicago.com) publishes both news and feature articles about gay and lesbian issues.

Pharmacies-- Walgreens, 757 N. Michigan Ave. (tel. 312/664-4000), is open 24 hours. The other big pharmacy chain in town, Osco Drugs, has a toll-free number (tel. 800/654-6726) that you can call to locate the 24-hour pharmacy nearest you.

Police-- For emergencies, call tel. 911. This is a free call (no coins required). For nonemergencies, call tel. 311.

Post Office-- The main post office is at 433 W. Harrison St. (tel. 312/983-8182); free parking is available. You also find convenient branches in the Sears Tower, the Federal Center Plaza at 211 S. Clark St., the James R. Thompson Center at 100 W. Randolph St., and a couple of blocks off the Magnificent Mile at 227 E. Ontario St.

Radio-- WBEZ (91.5 FM) is the local National Public Radio station, which plays jazz in the evenings. WFMT (98.7 FM) specializes in fine arts and classical music. WXRT (93.1 FM) is a progressive rock station whose DJs mix things up with shots of blues, jazz, and local music. On the AM side of the dial, you'll find talk radio on WGN (720) and WLS (890). News junkies should tune to WBBM (780) for nonstop news, traffic, and weather reports, and sports fans will find company on the talk station WSCR (1160).

Safety-- Chicago has all the crime problems of any urban center, so use your common sense and stay cautious and alert. Everyone has a different comfort level in unfamiliar terrain, so you'll have to decide for yourself where and when you want to venture. At night you might want to stick to well-lighted streets along the Magnificent Mile, River North, Gold Coast, and Lincoln Park (stay out of the park proper after dark, though), which are all high-traffic areas late into the night. Don't walk alone at night, and avoid wandering down dark residential streets, even those that seem perfectly safe. Muggings can -- and do -- happen anywhere.

After dark, you might want to avoid the Loop's interior, which gets deserted after business hours, as well as neighborhoods such as Hyde Park, Wicker Park (beyond the busy intersection of Milwaukee, Damen, and North aves.), and Pilsen, which border areas with more troublesome reputations. You can also ask your hotel concierge or an agent at the tourist visitor center about the safety of a particular area.

If you're traveling alone, avoid riding the El after the rush-hour crowds thin out. Of course, it's always smarter to ride with a group. Many of the El stations can be eerily deserted at night, when you'll have to wait around for 15 minutes or longer for the next train. In that case, it's a good idea to spring for a taxi. Buses are a safe option, too, especially nos. 146 and 151, which pick up along North Michigan Avenue and State Street and connect to the North Side via Lincoln Park.

Blue-and-white police cars are a common sight, and officers also patrol by bicycle downtown and along the lakefront and by horseback at special events and parades. There are police stations in busy nightlife areas, such as the 18th District station at Chicago Avenue and LaSalle Street in River North and the 24th District station (known as Town Hall) at Addison and Halsted streets.

Taxes-- The local sales tax is 8.75%. Restaurants in the central part of the city, roughly the 312 area code, are taxed an additional 1%, for a total of 9.75%. The hotel room tax is a steep 14.9%.

Time Zone-- All of Illinois, including Chicago, is located in the central time zone.

Transit Info-- The CTA has a useful number to find out which bus or El train will get you to your destination: tel. 836-7000 (from any area code in the city or suburbs) or TTY 836-4949.

Weather-- For the National Weather Service's current conditions and forecast, dial tel. 312/976-1212 (for a fee), or check the weather on the Web at www.ci.chi.il.us/Tourism/Weather/.