Going to Thailand from 17-21 - cheapest hostels to stay? places to go!

Hi everyone,
Im going to Thai on 17th of this month. Im going there with my friends ourself so Im just wonder if anyone can share your experience. Where is the cheapest hostel to stay? How to move around cities and where is the best places to go in Thai.
By the way, if anyone going there on the same day, properly we can join for a while.
Thanks

Bangkapi, Silom area has many cheap lodgings.
Within BKK there are many tourist attractions(just google) and shopping malls such as "Fashion Island", "The Mall",etc. Pattaya beach is another attraction.

Booking.com is one site. thee are many hotel site to help you. if you stay in the silom area there is the BTS(skytrain) near. that is the best way to get around. from the bts silom line you can go to the river and catch the boat to Grand Palace. much cheaper than a taxi. and for malls paragon is a great one.

it all depends on what you are looking to do.  :/