December is when winter really starts to gear up in New York. Temperatures generally range from 30° to 40° F, with snow possible but by no means guaranteed (there is often no snow on Christmas). But conditions can fluctuate wildly. Be prepared with a warm coat, hats and gloves. And remember you can always duck into a nearby store or coffee shop after a long walk out in the cold.

Update (December 23rd): We just got a big snowfall over the weekend, so the whole city is currently blanketed. It's pretty messy and there huge ice puddles at all the curb corners. Temperatures are staying steady in the high 20s / lows 30s.

It's going to warm up slightly when you arrive, but not much. Definitely come prepared for cold. Another snowfall might catch you on New Year's Eve.

You'll best be served by some combination of walking, taxis, and the subway.

Manhattan is extremely walkable and casual strolls are by far the best way to experience the variety of its neighborhoods firsthand. The subway is fast and convenient for longer distances in an uptown / downtown direction (but not so much from west to east). Taxis are your fastest and most convenient option, but they're also the most expensive and can get bogged down in Midtown's congested streets during weekdays in the daytime.

To hail a taxi, simply stand on the corner of the street with your arm outstretched and wait. If the center number in the taxi's sign is lit up (see picture), the taxi is available. Otherwise, it's busy with other passengers.

Once you enter the taxi, the driver starts the fare meter, which you can easily see and monitor. The current fare rate is $2.50 upon entry and $0.40 for every fifth mile, with minor surcharges for nights and traffic backups. This does not include a tip, which should be 15 to 20 percent as service merits. Here are some example fares to give you a practical sense of costs:

• Times Square to your hotel (40 blocks, 1.9 miles): $9 with tip
• SoHo to Rockefeller Center (60 blocks, 3 miles): $12 with tip

New York's subway may not be the cleanest, fastest, or most reliable mass transit system. But it remains one of the best ways to travel within the city, particularly during the daytime hours when road traffic can be a non-moving nightmare.

Manhattan is saturated with subway stations, so you'll never be more than a few minutes walk from one no matter where you are. A complete map is available here, but you should pick up a free printed copy from the agent booth in any station.

When you first enter the subway system, you'll need to purchase a MetroCard from the station agent or an automated machine. MetroCards come in two flavors. "Regular" MetroCards can be purchased for any price and permit access to the system for $2 per ride. "Unlimited" MetroCards permit unlimited rides for a single person for a set period of time. For your trip, a 7-day MetroCard ($25) is your best value.

The subway is open 24 hours, 7 days per week, and is safe (and crowded) at all hours of the day and night. However, scheduled service disruptions are very common on weekdays between midnight and 5 AM and on weekends. During these times, be extra careful to read the announcements that are posted up in all subway stations. If an announcement is unclear, ask a station agent or fellow traveler. Otherwise you may find your train skipping your intended stop, running down the wrong route, or not running at all.

Some more tips:

• Access is granted by swiping your MetroCard through a groove on a turnstile. Hold the MetroCard face-up in your right hand, with the front side facing you. Pass the card through the groove from back to front with a quick, steady motion. Once the turnstile recognizes your fare you'll be permitted to pass through.
• Your MetroCard works on all city buses with the same fare structure as the subway.
• All stations include neighborhood street maps near the agent booth which are useful for finding your way from the station to your intended destination.
• If you're ever lost or confused, don't hesitate to ask a fellow traveler. New Yorkers are particularly friendly and helpful in this regard, probably because they understand better than anyone the frustrations of making sense of this large, chaotic system.