To help you get your bearings in London, don't neglect visitors' centers. They're often an invaluable resource for everything from hotels to theater tickets. The following are some of the best:

London Tourist Board
1 Warwick Row
SW1 E5ER
Victoria Station
020-6932-2000
Easter-Oct Daily 8am-7pm, Nov-Easter Mon-Sat 8am-6pm, Sun 9am-4pm

Britain Visitor Centre
1 Regent St
SW1Y 4LR
Haymarket
In person only.
Jul-Sep Mon-Fri 9am-6:30pm, Sat-Sun 10am-4pm

VisitBritain
Thames Tower
Black's Rd
W6 9EL
Hammersmith
020-8846-9000

If you should run into trouble, the emergency number for the police, fire department, or ambulance is 999.