To put it simply, Bangkok can seem like a  labyrinth to new arrivals in the city. The sprawling expressways and  overpasses, huge new Skytrain and crowded streets full of vendors give  the place a distinct Blade Runner-esque feel. Causing even further  confusion is the lack of a true "center" to the city, with various  districts scattered throughout town. On the positive side, the Skytrain  has made it much easier to get around, and taxis, 
tuk-tuks,  buses and motorcycle taxis are plentiful. Get your bearings by reading  the following guide and it will not take long for you to be seduced by  the glorious chaos and charm of the "City of Angels."
Phra Nakorn
The  most heavily visited area, at least during the day, is Ko Rattanakosin  (Rattanakosin Island), Bangkok's old city on the eastern bank of the  Chao Phraya River. Here you will find fantastic examples of historical  architecture such as the glittering Grand Palace , Wat Phra Keo , Wat  Pho , Wat Mahathat , the Golden Mount and Wat Suthat . The city's  founding pillar, Lak Mueang , is also located in this district, as are  the National Museum , National Theater and National Gallery . If you are  keen on seeing something completely out of the ordinary, pop across the  river to the Museum of the Department of Forensic Medicine. Sanam Luang  is about the only green spot on the "island," which is not really an  island but would have seemed like one in the old days before the many  canals linking the area to the river had not yet been filled in.
Thonburi
Bangkok was once referred to as "The Venice of the East," but today the 
klongs, or canals, are concentrated in Thonburi, an area lying to the west of the Chao Phraya River. You can take a 
klong  tour, typical stops include Wat Arun and the museum of the Royal Barges  . Buses heading south from Bangkok leave from Sai Tai bus terminal,  located here.
Banglampoo and Thewet
Backpackers  head for the Banglampoo and Thewet districts. Near the Democracy  Monument on Khao San Road you can find some good souvenir shopping. This  strip is lined with guest houses and cheap restaurants, none of which  stand out for their ambiance or cuisine. A mere stone's throw away along  Phra Arthit Road, some great restaurants and bars come to life at  night. Following the eastern bank of the Chao Phraya, you will come to  an area with a laid-back, cosmopolitan feel that is frequented by  students from the nearby universities of Thammasat and Silpakorn. 
Dusit
The  Dusit district offers plenty of tourist attractions. Vimanmek Palace ,  Wat Benchamabophit , Suan Pakkard Palace and Dusit Zoo are all found  here. There is not much in the way of hotels or restaurants, but a small  artsy area popular with local students has sprung up on Rachawithee Soi  34.
Phayathai/Chatuchak
Northern  Bangkok's touristic highlight is Chatuchak Weekend Market , best reached  by catching the Skytrain. Mor Chit bus terminal is located near the  same stop, which is handy to know if you want to catch an  interprovincial bus heading north or northeast. This is also a major  transport hub, with the Skytrain and plenty of buses passing through.  Mah Boon Krong is the largest shopping center in the district, and  serves as a local transit hub and good orientation point. 
Pathumwan
Young  Thais and keen shoppers head for the area around Siam Square , a  shopping paradise - unless you are a tall Western woman looking for  off-the-rack clothes or shoes. The huge array of dining options along  this stretch include Auberge Daband and the Erawan Tea Room .
There  is plenty of selection in malls such as Siam Center and Siam Discovery  Center , Centerpoint (the most popular teenage hangout), and the World  Trade Center . A walk away from the latter stands Panthip Plaza, also  known as heaven for computer geeks, and possibly the best place to get  deals on computers in Southeast Asia. The non-shopper can retreat to the  sanctuary of Jim Thompson's House and Museum . There is a cluster of  hotels in this area, and popular restaurants such as the Hard Rock Cafe  are also found here. Heading east along Ploenchit Road and Sukhumvit  Road, you can orchestrate a shopping extravaganza at either the street  stalls that spring up at the beginning of Sukhumvit and stretch to Soi  Asoke or at department stores such as Central Chidlom .
Sathorn/Silom/Bangrak
The  Sathorn/Silom area forms the core of Bangkok's Central Business  District, although the Stock Exchange of Thailand is located some  distance away on Ratchadaphisek Road. The area encompasses a number of  embassies and hotels, such as the Banyan Tree, Sukhothai and Dusit Thani  . Silom Road offers more shopping opportunities, including the Patpong  Night Market . Sri Maha Uma Devi Temple is also located in this  district. Restaurants abound, particularly around Convent Road. Head for  nearby Lumpini Park for a break in a rare patch of green.
If you  head west along Sathorn or Silom Road, you will come to Charoen Krung  ("New") Road and back to the Chao Phraya River. A tram used to run along  this road, but these days hardly anything does - the traffic is too  thick! This is another popular hotel area, with such luxurious hotels as  The Oriental , The Peninsula , the Shangri-La , the Royal Orchid  Sheraton and the Marriott Spa Resort all overlooking the river. Take a  sunset cruise or dine in one of the many restaurants along the majestic  river, such as Yok Yor Marina and Restaurant . The River City Shopping  Complex sells a huge array of antiques and is worth a browse. 
Chinatown and Pahurat
North  along the river lies hectic Chinatown and Pahurat, an Indian district.  Here you will find Wat Traimit , but the area is best known for its  shopping. Yaowarat Road has loads of gold shops, while Sampeng Lane has  everything from hair accessories to shoes, all at bargain prices.  Farther north you will come to Pak Klong Talat with its colorful fresh  flowers.
Outside the City
There are also a  number of attractions to be found in the outlying areas of Bangkok and  adjacent provinces, including King Rama IX Royal Park , Nonthaburi, the  Ancient City , Damnoen Saduak Floating Market and Ayutthaya , a trip to  which usually incorporates a visit to Bang Pa-In Summer Palace .
from: travel.yahoo.com/p-travelguide-191501667-bangkok_vacations-i;_ylt=AqxEu9PIP0ilUCqJsmD1JphiFWoL