Where to Stay
Try to stay on or near Koh San Road. D&D and The Palace are the best hotels in the area, but they aren’t very cheap and usually require reservations beforehand.
Where to Party
Koh San Road is a great place to start your night and the best place to round up a crew. The street is full of bars at night and even has a few clubs (including one called “The Club”). This city really has something for every type of partier- electronic clubs, strip clubs, sports bars, etc. and they are all pretty happening (especially if you are there in the week leading up to a full moon party). Most nights should end watching the sunrise telling your friends crazy stories about the night. Most backpackers don’t venture outside of the Koh San area at night, but if you are looking for more upscale places there are some clubs a short taxi ride away in Sukhumvit. If you are really into the seedier scene (or want to see where the Hangover 2 was filmed), check out Soi Cowboy. Don’t expect to party with locals (unless they are prostitutes/ladyboys).
You can hear some good house music in the clubs, but normally you will hear Top 40.
During the Day
Try weird foods (like bugs), buy cheap clothing and check out some temples. Make sure to get at least one massage every day – these are all over. In the evening, before raging, go see a ping-pong show (tons of people will offer this to you on Koh San).