QUOTE(salemk @ Jul 7 2010, 09:20 PM)

If anyone knows which airport(s) to use and why would be great.
I think I'm looking at cheapest but if you know of a better reason let me know too.
I'll be traveling around for a month and need to fly into Thailand afterward.
I dont have a problem flying into Indonesia or another country first as long as its cheaper.
Most of the international flights land at Bangkok, Suvarnabhumi Airport. (BKK.) I think there is a couple small airlines that still use Don Muang Airport but the majority of flights arrive and leave from BKK.
There are some discount airlines that fly from Manila (MNL) to Thailand. Some of these airlines may use Clark Airfield, Diosdado Macapagal International Airport, near Angeles City. This airport is not close to Manila if you are not familiar with the Philippines.
I prefer to use Philippine Airlines when flying between MNL and BKK. One reason is that I like their departure and arrival times. PAL is tight with their weight allowances for carry on and checked in bags but the discount airlines are even worse. A local Manila travel agency can help you out on airline choices.
Make sure that you can actually fly into Thailand and stay 30 days! If you can stay 30 days or not will depend on the passport you are traveling under. If you are from the UK, US, Oz, NZ and many places in Europe you can get 30 days entry for free at the airport. Other countries may have different requirements.
So, if you want to go with the cheapest means possible then check your connection times, check the weight allowances (if your bags are too heavy you pay a fee.!) Check where you will actually fly from - physical geographic area - and where you land at! If you are in Manila and you have to fly out of Clark and you wait until the last minute you may have to pay $50 for a taxi ride! Also, if you are landing in Thailand in the middle of the night you still pay for a full night in a hotel but only use if for part of the time!
If you need any hotel recommendations mention a price range. Use a baht figure. Don't blow off Bangkok and try to fly out immediately. See the city, take some tours, eat some good Thai food, etc.
Read up on Thailand and see what interests you before you take off. But read the visa requirements first.
http://www.mfa.go.th/web/2482.php?id=2490http://www.mfa.go.th/web/2482.php?id=2491Within Thailand you have excellent train and bus service. There are some cheap flights connecting major cities too. Several regional airports. Some international flights also fly into Chiang Mai and Phuket but most tourists use BKK.
Google up "what to see and do in Thailand" and you will get some additional help. Start in Bangkok and end there.
Good luck.