• I want to know the hidden spots not in a travel guide book!
• I want to go to local market

Hello Chan,
There are so many places to visit in Bangkok it is difficult to tell you. Depending on what you are interested in seeing there is a wide variety of cultural, shopping, eating and partying places to visit. My girlfriend is native Thai person (who speaks English OK) and knows many good places that are not in travel books to visit, eat, and experience when you visit Bangkok - also she is very good shopper and can show you many good places.
Hotels in Bangkok are not expensive and they have many services to care for you.
If you want more detailed information feel free to write me and we can talk about how to plan your visit here.
Good Luck and have fun when you visit!
Mitch