There are currently four Airlines,used by tourists, in Myanmar.
The fifth one Myanmar Airways (as against MAI-Myanmar airways International) is not recommended and Agents will avoid booking on them for you wherever possible.
All of them use ATr42/72 Turbo props and a couple have jet aircraft (F100) Their aircraft types and their network and schedule are on their web sites,but generally not their pricing.
Non of them currently have an eticket on-line booking system and some tickets are still hand written.
Some of them also have a web booking system whereby you can reserve tickets by email for collection and payment on arrival in Myanmar.
By far the best way is to reserve your tickets through a local Agent,there are many recommended on these forums. The cost will be no more than the ticket value,sometimes a few $'s less, but the big advantage is if there are schedule or time changes the Agent can contact you and advise of the change.
Do beware of a French Travel Agent masquerading as Yangon Air and Air Mandalay, their web site has a HYPHEN in the web name and looks genuine and they ask for 50% deposit,balance on collection in Myanmar. There ownership is shown at the foot of the page with a Paris and Bangkok address
Whilst many travellers have used them successfully there have been reports here and on Thorntree of tourists turning up and finding the airline had no booking and having to buy a new ticket. This happened to me once on their Lao-Air site.
The best that can happen is that you lose some money,the worst is that you lose your money and there are no seats available and you are stuck.
If you are interested in airlines and schedules this link to Yangon will be useful. Not so many years ago there were only a few International airlines flying into Yangon-now the pages are full of arrivals and departures. Internal flights are listed but not logged for timings. Input RGN into the airport box on the right.
SSEdited: 7:01 am, October 28, 2012