How much does apartment rent for in bangkok, furnish and not furnish 6 month lease to a year, Do you have to put down a lot of money? What are some good area to rent.

You need to know how much you can afford and what type/size of property you expect/want.

From 3000 to 200.000 furnished is more expensive than unfurnished. You have to pay one or two month deposit. 

Most areas are good. Depends on what you are looking for.