As far as currency goes, they have Currency exchange booths at the airport, but the rates are not the best. I would recommend getting a small amount at the airport if you can not get any in advance. The better options for currency exchange are as follows. Here is a site that will tell you what the current exchange rates are: http://www.xe.com/ucc/
1) Contact a local bank in advance of your trip and tell them you need to get currency for your trip. You may need to give them a couple days to order it, but you should get a good rate.
2) Go to a bank or ATM once you are in Thailand. A lot of the Malls and big shopping centers like Big C and Lotus have currency exchange booths that give much better rates than the airport.
Also, a good tip for currency exchange, when you leave the country, most currency exchange places won’t accept coins back, only paper money. Try to convert all your coins to paper money at a shop before you leave.
Hope that info helps. Keep checking back on my traveling tips sections for more tips about Thailand and traveling in general.