Mix of old and new in Thailands largest City: Bangkok
Bangkok! Oriental setting, the city don't know, what the City is getting...Murray Head One Night in Bangkok lyrics. Apparently the song was banned in Thailand according to Wikipedia: In 1985, Thailand's Mass Communications Organization banned One Night in Bangkok, saying its lyrics "cause misunderstanding about Thai society and show disrespect towards Buddhism." Links to the song can be found in Wiki's link above. I would not count on the song to give you an accurate description of what you'll find in Bangkok.
Air Travel
Arriving by air is the best way to get to Thailand for those of us living entirely on the other side of the world. It is about an 18 hour trip depending upon your chosen airline. Korean air and ANA have amazing food and the service is bar none (especially if you are used to rude American flights).
Bangkok's airport is extremely modern with a mix of concrete, windows and metal. It is located fairly far from the city. Expect a 30-45 minute cab ride to town. It's best to arrive at night when the traffic is lightest. The city reminds me of New York, it doesn't sleep. So while arriving in the middle of the night in Ohio might consist of waking up the Inn-keeper, you will never disturb the night staff at the Bangkok hotels as they are abuzz even at 1:30 am.
Siam Discovery Center-Skytrain
You should know that Siam is not said the way we say it in the US. It is said "see-am." And you will impress any Thai native if you say it correctly. The Siam Discovery Center is a glitzy indoor shopping mall with escallators, exotic imported food, clothing, and accessories. Do not expect Thai prices if you are shopping here. Expect American prices. You can find shippers and ATMs here. Use them, because once you leave the center they are harder to find and don't feel quite as safe.
The Skytrain, part of the BTS, can easily get you to the Siam Center if you stay at a hotel along the route. When we visited there were two main lines. A visit to the website shows that more are in the process of being built. The Skytrain is very easy to use and very clean due to it being so new. It runs along Thanon Sukhumvit and Silom and is above the street literally in the air, therby avoiding traffic. It is the fastest way to travel, but destinations are limited.
Chatuchak and Night Markets
Chatuchak is a famous weekend market in Bangkok. Wikipedia describes it as the largest market in the world. When you go, expect a gigantic flea market with illegal blackmarket mechandise in some stalls. To get there, take the Skytrain on the Sukhumvit line to Mo Chit station. It is another 5 minute walk to the market.
Unfortunately, if you are not in Bangkok on a weekend you will miss the Chatuchak market but you can still attend a night market. You can hail a cab and ask the driver to take you to a night market and you will be there within 10 minutes. They exist all over town. Expect stalls with scarves, carvings, bars, restaurants, sometimes live music--a lot of it American with a Thai accent.
Food-street vendors
Do not be afraid of the street vendors, but make sure the food you eat is piping hot. Noodle soups that are served in plastic bowls and eaten on the spot are excellent! Steer clear of fish sitting out and anything put into little plastic baggies with elastics. The meat on a stick usually has flour or something mixed in but is safe if it's right off the heat. Pointing to the one you want works best. Most of the food we ate from restaurants was very safe, though not all of it was good! Some of the street vendors were better and far cheaper. You can get two big bowls of soups with veggies, meat and noodles for about $3, Chang beer will cost another $1.50.
Cabs, Tuk-Tuks, Motorbikes
I would not recommend renting a motorbike in Bangkok unless you like to live dangerously and have good life insurance. The traffic is such that motorbikes are the fastest way to get from place to place, and the cheapest. You can hire a motorbike taxi but they weave in and out of traffic dangerously. It's not the safest option.
The cabs are plentiful and fairly cheap--just make sure you agree on a price before hand or ask the driver to set the meter. If he doesn't...get out of the cab. You don't want to get ripped off. Cabs are the best way to get places that are more than 15 minutes away...and they have airconditioning! It should only cost you about $15 to get from the airport to your hotel if it is not more than 45 minutes away.
The Tuk-tuk is great if you are not going far and have luggage. If you are sensitive to exhaust you will not like the tuk-tuk's smell. Most of the men driving these own them, so they make their own prices. They are fairly fast because they can weave in and out of traffic to an extent but expect to feel a bit nauseated after riding in one due to the smell and constant side to side motion.