I will be flying to Southeast Asia from New York en route to teach English in Thailand. I'd also like to travel to Laos, Cambodia, Vietnam, Myanmar, and Singapore. If my budget permits I would also like to travel to India, Nepal, Sri Lanka, basically anywhere I can reach from Thailand without TOO much trouble.

I want to fly out at the beginning of October. Should I buy a one-way ticket since I will be in Bangkok for a year? Should I buy the ticket to another city and work my way over to Bangkok? Where should I go first? Any suggestions on how I can get to at least some of these places efficiently? So many decisions, I don't know where to start! Help!